The information in this preliminary pricing supplement is not complete and may be changed. This preliminary pricing supplement and the accompanying product supplement, underlying supplement, prospectus supplement and prospectus are not an offer to sell these securities, nor are they soliciting an offer to buy these securities, in any state where the offer or sale is not permitted.

Citigroup Global Markets Holdings Inc. $ Bearish Autocallable Absolute Return S&P 500® Index-Linked Notes due All Payments Due from Citigroup Global Markets Holdings Inc. Fully and Unconditionally Guaranteed by Citigroup Inc.

Unlike conventional debt securities, the notes offered by this pricing supplement do not pay interest. The amount that you will be paid on your notes on the maturity date (expected to be the second business day after the scheduled determination date, which is expected to be between 12 and 14 months after the trade date) is based on the performance of the S&P 500^® Index (the “underlier”) as measured from the trade date to and including the determination date, unless the notes are automatically called.

Your notes will be automatically called if, on any call observation date (each day from but excluding the original issue date to but excluding the determination date), the closing level of the underlier is less than the initial underlier level (to be determined on the trade date) by more than the threshold percentage of 20%. The initial underlier level will be set on the trade date and may be higher or lower than the actual closing level of the underlier on the trade date. If your notes are automatically called, you will be repaid the stated principal amount of your notes on the corresponding call payment date (the second business day after the relevant call observation date) but will not receive any positive return on your investment.

If your notes are not automatically called, then your payment at maturity will be based on the underlier return, which is the percentage increase or decrease in the level of the underlier from the initial underlier level to the final underlier level on the determination date. If the final underlier level is greater than or equal to the initial underlier level, then you will be repaid the stated principal amount of your notes at maturity and will receive a contingent return (set on the trade date and expected to be between 3.49% and 4.10%). If the final underlier level is less than the initial underlier level but not by more than the threshold percentage, then you will receive a positive return at maturity equal to the absolute value of the underlier return. For example, if the underlier return is -15%, your return will be 15%. If the final underlier level is less than the initial underlier level by more than the threshold percentage, then you will be repaid the stated principal amount of your notes at maturity but will not receive any positive return on your investment. If your notes are not automatically called and the final underlier level is greater than or equal to the initial underlier level, the return on your notes will be limited to the contingent return equal to between 3.49% and 4.10% (to be set on the trade date). If the final underlier level is less than the initial underlier level, you will receive a positive return only if the level of the underlier has decreased by not more than the threshold percentage. As a result of the threshold percentage, the maximum return on your notes will be 20.00%. 

By purchasing these notes, you primarily are taking the bearish view that the level of the underlier will decline such that the final underlier level on the determination date will be less than the initial underlier level, but not by more than the threshold percentage. You are also taking that view that, even if the value of the underlier increases, the final underlier level will not be greater than between 103.49% and 104.10% of the initial underlier level.

If your notes are not automatically called, on the maturity date, for each $1,000 stated principal amount note you then hold, you will receive an amount in cash equal to:

The notes are unsecured senior debt securities issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc. All payments on the notes are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc. If Citigroup Global Markets Holdings Inc. and Citigroup Inc. default on their obligations, you may not receive any amount due under the notes. The notes will not be listed on any securities exchange and may have limited or no liquidity.

Investing in the notes involves risks not associated with an investment in conventional debt securities. See “Summary Risk Factors” beginning on page PS-7.

(1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the notes on the trade date will be between $967.40 and $987.40 per note, which will be less than the issue price. The estimated value of the notes is based on proprietary pricing models of Citigroup Global Markets Inc. (“CGMI”) and our internal funding rate. It is not an indication of actual profit to CGMI or other of our affiliates, nor is it an indication of the price, if any, at which CGMI or any other person may be willing to buy the notes from you at any time after issuance. See “Valuation of the Notes” in this pricing supplement.

(2) CGMI, an affiliate of the issuer, is the underwriter for the offering of the notes and is acting as principal. The total underwriting discount in the table above assumes that the underwriter receives an underwriting discount for each note sold in this offering. For more information on the distribution of the notes, see “Summary Information—Key Terms—Supplemental plan of distribution” in this pricing supplement. In addition to the underwriting discount, CGMI and its affiliates may profit from expected hedging activity related to this offering, even if the value of the notes declines. See “Use of Proceeds and Hedging” in the accompanying prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the notes or determined that this pricing supplement and the accompanying product supplement, underlying supplement, prospectus supplement and prospectus are truthful or complete. Any representation to the contrary is a criminal offense.

The notes are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency, nor are they obligations of, or guaranteed by, a bank.

The notes are part of the Medium-Term Senior Notes, Series N of Citigroup Global Markets Holdings Inc. This pricing supplement is a supplement to the documents listed below and should be read together with such documents, which are available at the following hyperlinks:

Citigroup Global Markets Inc.

Pricing Supplement No. 2024-USNCH21830 dated----------, 2024

The issue price, underwriting discount and net proceeds listed above relate to the notes we sell initially. We may decide to sell additional notes after the date of this pricing supplement, at issue prices and with underwriting discounts and net proceeds that differ from the amounts set forth above. The return on your investment in notes will depend in part on the issue price you pay for such notes. CGMI may use this pricing supplement in the initial sale of the notes. In addition, CGMI or any other affiliate of Citigroup Inc. may use this pricing supplement in a market-making transaction in a note after its initial sale.

SUMMARY INFORMATION

Key Terms

Issuer: Citigroup Global Markets Holdings Inc., a wholly owned subsidiary of Citigroup Inc.

Guarantee: all payments due on the notes are fully and unconditionally guaranteed by Citigroup Inc.

Underlier: the S&P 500^® Index (ticker symbol: “SPX”), as maintained by S&P Dow Jones Indices LLC (the “underlier sponsor”). The underlier is referred to as the “underlying index” and the underlier sponsor is referred to as the “underlying index publisher” in the accompanying product supplement.

Stated principal amount: each note will have a stated principal amount of $1,000

Purchase at amount other than the stated principal amount: the amount we will pay you on a call payment date or the maturity date, as applicable, for your notes will not be adjusted based on the issue price you pay for your notes, so if you acquire notes at a premium (or discount) to the stated principal amount and hold them to a call payment date or to the maturity date, as applicable, it could affect your investment in a number of ways. The return on your investment in such notes will be lower (or higher) than it would have been had you purchased the notes at the stated principal amount. See “Summary Risk Factors — If You Purchase Your Notes at a Premium to the Stated Principal Amount, the Return on Your Investment Will Be Lower Than the Return on Notes Purchased at the Stated Principal Amount and the Impact of Certain Key Terms of the Notes Will Be Negatively Affected” on page PS-11 of this pricing supplement.

Cash settlement amount (paid on the maturity date): if the notes are not automatically called, on the maturity date, for each $1,000 stated principal amount of notes you then hold, we will pay you an amount in cash equal to:

Initial underlier level (to be set on the trade date, which may be an intraday level and which may be higher or lower than the actual closing level of the underlier on the trade date):

Final underlier level: the closing level of the underlier on the determination date, except in the limited circumstances described under “Description of the Notes — Certain Additional Terms for Notes Linked to an Underlying Index — Discontinuance or Material Modification of an Underlying Index” on page EA-24 of the accompanying product supplement and subject to adjustment as provided under “Description of the Notes — Certain Additional Terms for Notes Linked to an Underlying Index — Determining the Closing Level” on page EA-20 of the accompanying product

supplement and “Description of the Notes — Certain Additional Terms for Notes Linked to an Underlying Index — Consequences of a Market Disruption Event; Postponement of a Valuation Date” on pages EA-20 to EA-24 of the accompanying product supplement.

Underlier return: the quotient of (i) the final underlier level minus the initial underlier level divided by (ii) the initial underlier level, expressed as a percentage

Absolute underlier return: the absolute value of the underlier return, expressed as a percentage (e.g., a -15.00% underlier return will equal a 15.00% absolute underlier return)

Threshold percentage: 20.00%

Contingent return (to be set on the trade date): expected to be between 3.49% and 4.10%

Automatic redemption: If the closing level of the underlier on a call observation date is less than 80.00% of the initial underlier level, the notes will be automatically called on the applicable call observation date and, for each $1,000 stated principal amount of the notes, we will pay you an amount in cash equal to $1,000 on the corresponding call payment date

Call observation dates: each day from but excluding the original issue date to but excluding the determination date, excluding any date or dates on which the calculation agent determines that a market disruption event occurs or is continuing or that the calculation agent determines is not a scheduled trading day

Call payment dates: expected to be the second business day after the corresponding call observation date

Trade date: . The trade date is referred to as the “pricing date” in the accompanying product supplement.

Original issue date (settlement date) (to be set on the trade date): expected to be the fifth scheduled business day following the trade date. See “Supplemental plan of distribution” below for additional information.

Determination date (to be set on the trade date): expected to be between 12 and 14 months after the trade date. The determination date is referred to as the “valuation date” in the accompanying product supplement and is subject to postponement if such date is not a scheduled trading day or if certain market disruption events occur, as described under “Description of the Notes — Certain Additional Terms for Notes Linked to an Underlying Index — Consequences of a Market Disruption Event; Postponement of a Valuation Date” on pages EA-20 to EA-24 of the accompanying product supplement.

Maturity date (to be set on the trade date): expected to be the second business day after the scheduled determination date

No interest: the notes will not bear interest

No listing: the notes will not be listed on any securities exchange or interdealer quotation system

Business day: as described under “Description of the Notes — General” on page EA-20 in the accompanying product supplement

Scheduled trading day: as described under “Description of the Notes — Certain Additional Terms for Notes Linked to an Underlying Index — Consequences of a Market Disruption Event; Postponement of a Valuation Date” on page EA-22 of the accompanying product supplement

Supplemental plan of distribution: Citigroup Global Markets Holdings Inc. expects to sell to CGMI, and CGMI expects to purchase from Citigroup Global Markets Holdings Inc., the aggregate stated principal amount of the offered notes specified on the front cover of this pricing supplement. CGMI proposes initially to offer the notes to the public at the issue price set forth on the cover page of this pricing supplement, and to certain unaffiliated securities dealers at such price less a concession not in excess of 1.00% of the stated principal amount. In addition to the underwriting discount, CGMI and its affiliates may profit from expected hedging activity related to this offering, even if the value of the notes declines. See “Use of Proceeds and Hedging” in the accompanying prospectus.

CGMI is an affiliate of ours. Accordingly, this offering will conform with the requirements addressing conflicts of interest when distributing the securities of an affiliate set forth in Rule 5121 of the Financial Industry Regulatory Authority. Client accounts over which Citigroup Inc. or its subsidiaries have investment discretion will not be permitted to purchase the notes, either directly or indirectly, without the prior written consent of the client.

Secondary market sales of securities typically settle two business days after the date on which the parties agree to the sale. Because the settlement date for the notes is more than two business days after the trade date, investors who wish to sell the notes at any time prior to the second business day preceding the original issue date will be required to specify an alternative settlement date for the secondary market sale to prevent a failed settlement. Investors should consult their own investment advisors in this regard.

See “Plan of Distribution; Conflicts of Interest” in the accompanying product supplement and “Plan of Distribution” in each of the accompanying prospectus supplement and prospectus for additional information.

A portion of the net proceeds from the sale of the notes will be used to hedge our obligations under the notes. We expect to hedge our obligations under the notes through CGMI or other of our affiliates, or through a dealer participating in this offering or its affiliates. CGMI or such other of our affiliates or such dealer or its affiliates may profit from this expected hedging activity

even if the value of the notes declines. This hedging activity could affect the closing level of the underlier and, therefore, the value of and your return on the notes. For additional information on the ways in which our counterparties may hedge our obligations under the notes, see “Use of Proceeds and Hedging” in the accompanying prospectus.

ERISA: as described under “Benefit Plan Investor Considerations” on pages EA-50 and EA-51 in the accompanying product supplement

Calculation Agent: CGMI

CUSIP: 17331UNC7

ISIN: US17331UNC70

HYPOTHETICAL EXAMPLES

The table, examples and chart below are provided for purposes of illustration only. They should not be taken as an indication or prediction of future investment results and are intended merely to illustrate the impact that various hypothetical closing levels of the underlier on a call observation date or on the determination date could have on whether the notes are called or the cash settlement amount at maturity.

The table, examples and chart below are based on a range of closing levels for the underlier that are entirely hypothetical; no one can predict what the closing level of the underlier will be on any call observation date or on the determination date. The underlier has been highly volatile in the past — meaning that the underlier level has changed considerably in relatively short periods — and its performance cannot be predicted for any future period. Investors in the notes will not receive any dividends on the stocks that constitute the underlier. The table, examples and chart below do not show any effect of lost dividend yield over the term of the notes. See “Summary Risk Factors—Investing in the Notes Is Not Equivalent to Investing in the Underlier or the Stocks that Constitute the Underlier” below.

The information in the table, examples and chart below reflects hypothetical returns on the notes assuming that they are purchased on the original issue date at the stated principal amount and held to a call payment date or the maturity date, as applicable. If you sell your notes in a secondary market prior to an applicable call payment date or the maturity date, your return will depend upon the value of your notes at the time of sale, which may be affected by a number of factors that are not reflected in the table or examples below such as interest rates, the volatility of the underlier and our and Citigroup Inc.’s creditworthiness. Please read “Summary Risk Factors—The Value of the Notes Prior to Maturity Will Fluctuate Based on Many Unpredictable Factors” in this pricing supplement. It is likely that any secondary market price for the notes will be less than the issue price.

The information in the table, examples and chart also reflects the key terms and assumptions in the box below.

Moreover, we have not yet set the initial underlier level that will serve as the baseline for determining the underlier return and the amount that we will pay on your notes on a call payment date or at maturity. We will not do so until the trade date. As a result, the actual initial underlier level may differ substantially from the underlier level prior to the trade date and may be higher or lower than the closing level of the underlier on the trade date.

For these reasons, the actual performance of the underlier over the life of your notes, as well as whether the notes are automatically called on a call observation date and the amount payable at maturity, may bear little relation to the hypothetical examples shown below or to the historical underlier levels shown elsewhere in this pricing supplement. For information about the historical levels of the underlier during recent periods, see “The Underlier — Historical Closing Levels of the Underlier” below. Before investing in the offered notes, you should consult publicly available information to determine the levels of the underlier between the date of this pricing supplement and the date of your purchase of the offered notes.

If your notes are automatically called on a call observation date (i.e., on the applicable call observation date the closing level of the underlier is less than 80.000% of the initial underlier level), the amount in cash that we would deliver for each $1,000 stated principal amount of the notes on the applicable call payment date would be 100.000% of the stated principal amount of the notes. If, for example, the closing level of the underlier on a call observation date were determined to be 65.000% of the initial underlier level, your notes would be automatically called and the amount in cash that we would deliver on your notes on the corresponding call payment date would be 100.000% of the stated principal amount of your notes or $1,000 for each $1,000 stated principal amount of your notes.

If your notes are not automatically called on any call observation date (i.e., the closing level of the underlier is greater than or equal to 80.000% of the initial underlier level on each call observation date), the cash settlement amount we would deliver for each $1,000 stated principal amount note on the maturity date will depend on the performance of the underlier on the determination date, as shown in the table below. The table below assumes that the notes have not been automatically called on a call observation date and reflects hypothetical cash settlement amounts that you could receive on the maturity date.

The levels in the left column of the table below represent hypothetical final underlier levels and are expressed as percentages of the initial underlier level. The amounts in the right column represent the hypothetical cash settlement

amounts, based on the corresponding hypothetical final underlier level (expressed as a percentage of the initial underlier level), and are expressed as percentages of the stated principal amount of a note (rounded to the nearest one-thousandth of a percent). Thus, a hypothetical cash settlement amount of 100.000% means that the value of the cash payment that we would deliver for each $1,000 of the outstanding stated principal amount of the notes on the maturity date would equal 100.000% of the stated principal amount of a note, based on the corresponding hypothetical final underlier level (expressed as a percentage of the initial underlier level) and the assumptions noted above.

The Notes Have Not Been Automatically Called

If, for example, the notes have not been automatically called on a call observation date and the final underlier level were determined to be 25.000% of the initial underlier level, the cash settlement amount that we would deliver on your notes at maturity would be 100.000% of the stated principal amount of the notes, as shown in the table above. In addition, if the final underlier level were determined to be 150.000% of the initial underlier level, the cash settlement amount that we would deliver on your notes at maturity would be limited to 103.490% of the stated principal amount of the notes, as shown in the table above. If the final underlier level were determined to be 90.000% of the initial underlier level, the absolute underlier return would be 10.000% and the cash settlement amount that we would deliver on your notes at maturity would be 110.000% of the stated principal amount of the notes, as shown in the table above. However, you will benefit from the absolute underlier return only if the final underlier level is less than the initial underlier level but greater than or equal to 80.000% of the initial underlier level. As a result, you would not benefit from a final underlier level that is below 80.000% of the initial underlier level. In fact, a final underlier level that is below 80.000% of the initial underlier level will cause the cash settlement amount that we will deliver at maturity to be limited to 100.000% of the stated principal amount. Further, you should be aware that, even if the final underlier level is less than the initial underlier level, the cash settlement amount that we will deliver at maturity will be less than 103.490% of the stated principal amount if the final underlier level is less than 100.000% but greater than 96.510% of the initial underlier level, as shown in the table above.

The following chart also shows a graphical illustration of the hypothetical cash settlement amounts that we would pay on your notes on the maturity date, if the final underlier level (expressed as a percentage of the initial underlier level) were any of the hypothetical levels shown on the horizontal axis. The chart shows that any hypothetical final underlier level of greater than or equal to 100.000% (the section on and to the right of the 100.000% marker on the horizontal axis) would result in a hypothetical cash settlement amount of 103.490% of the stated principal amount of the notes. The chart also shows that any hypothetical final underlier level at or above 80.000% but below 100.000% (the section between the 80.000% and 100.000% markers on the horizontal axis) would result in a hypothetical payment amount that is greater than 100.000%, but less than or equal to 120.000%, of the stated principal amount of the notes. The chart further shows that any hypothetical final underlier level below 80.000% (the section to the left of the 80.000% marker on the horizontal axis) would result in a hypothetical payment amount that is equal to 100.000% of the stated principal amount of the notes.

The cash settlement amounts shown above are entirely hypothetical; they are based on levels of the underlier that may not be achieved on the determination date. The actual cash settlement amount you receive on the maturity date may bear little relation to the hypothetical cash settlement amounts shown above, and these amounts should not be viewed as an indication of the financial return on an investment in the notes. The actual market value of your notes on the maturity date or at any other time, including any time you may wish to sell your notes, may bear little relation to the hypothetical cash settlement amounts shown above, and these amounts should not be viewed as an indication of the financial return on an investment in the offered notes. The hypothetical cash settlement amounts on notes held to an applicable call payment date or the maturity date in the examples above assume you purchased your notes at their stated principal amount and have not been adjusted to reflect the actual issue price you pay for your notes. The return on your investment in your notes will be affected by the amount you pay for your notes. If you purchase your notes for a price other than the stated principal amount, the return on your investment will differ from, and may be significantly lower than, the hypothetical returns suggested by the above examples. Please read “Summary Risk Factors — The Value of the Notes Prior to Maturity Will Fluctuate Based on Many Unpredictable Factors” in this pricing supplement.

SUMMARY RISK FACTORS

You May Not Receive Any Positive Return on Your Investment in the Notes

You will receive a positive return on your investment in the notes only if the notes are not automatically called and the final underlier level is (i) greater than or equal to the initial underlier level or (ii) less than the initial underlier level by an amount that is not more than the threshold percentage. If the final underlier level is less than the initial underlier level by more than the threshold percentage, or if the notes are automatically called, you will receive only the stated principal amount of $1,000 for each note you hold at maturity or on the applicable call payment date. As the notes do not pay any interest, even if the notes are not automatically called and the underlier appreciates from the initial underlier level to the final underlier level, or depreciates by less than the threshold percentage, there is no assurance that your total return at maturity on the notes will be as great as could have been achieved on conventional debt securities of ours of comparable maturity.

The Notes Provide Limited Bearish Exposure to the Performance of the Underlier.

Provided that the notes are not automatically called, your return on the notes will be between 3.49% and 4.10% (set on the trade date) if the underlier appreciates from the initial underlier level to the final underlier level on the determination date. The only additional circumstance under which you will receive a positive return on the notes is if the notes are not automatically called and the level of the underlier declines such that the final underlier level on the determination date is less than the initial underlier level by not more than the threshold percentage. If the closing level of the underlier is less than 80.00% of the initial underlier level on a call observation date or the determination date, you will be repaid only the stated principal amount of your notes on the corresponding call payment date or at maturity, as applicable.

The Initial Underlier Level Will Be Determined at the Discretion of CGMI, as the Calculation Agent

The initial underlier level may be an intraday level of the underlier on the trade date, as determined by the calculation agent in its sole discretion, and may not be based on the closing level of the underlier on such trade date. The initial underlier level may be higher or lower than the actual closing level of the underlier on the trade date. Although the calculation agent will determine the initial underlier level in good faith, the discretion exercised by the calculation agent in determining the initial underlier level could have an impact (positive or negative) on the value of your notes. The calculation agent is under no obligation to consider your interests as a holder of the notes in taking any actions that might affect the value of your notes, including the determination of the initial underlier level.

The Notes Do Not Pay Interest

Unlike conventional debt securities, the notes do not pay interest. You should not invest in the notes if you seek current income during the term of the notes.

The Notes Are Subject to Automatic Redemption

If the closing level of the underlier is less than 80.00% of the initial underlier level on any call observation date, the notes will be automatically called and you will be repaid the stated principal amount of your notes on the corresponding call payment date but will not receive any positive return on your investment. Therefore, the term for your notes may be significantly reduced. You may not be able to reinvest the proceeds from an investment in the notes at a comparable return for a similar level of risk in the event the notes are called prior to maturity.

Your Potential Return on the Notes Is Limited

If the notes are not automatically called and the final underlier level is less than the initial underlier level but not by more than the threshold percentage, you will receive a positive return at maturity equal to the absolute value of that decline but

limited to 20%. If the final underlier level is greater than the initial underlier level, the cash settlement amount at maturity for each $1,000 stated principal amount of the notes will be limited to between $1,034.90 and $1,041.00 (set on the trade date). If the notes are automatically called or if the final underlier level is less than the initial underlier level by more than the threshold percentage, the cash settlement amount at maturity for each $1,000 stated principal amount of your notes will be limited to $1,000 (representing a return of 0%). Accordingly, the amount payable for each of your notes may be significantly less than your return had you invested directly in the stocks that constitute the underlier.

The Determination Date of the Notes Is a Pricing Term and Will Be Determined by the Issuer on the Trade Date

We will not determine the determination date until the trade date, so you will not know the exact term of, or the maturity date for, the notes at the time that you make your investment decision. The term of the notes could be as short as the shorter end of the determination date range described on PS-3, and as long as the longer end of the determination date range. You should be willing to hold your notes until the latest possible maturity date contemplated by the determination date range. The determination date selected by us could have an impact on the value of the notes. Assuming no changes in other economic terms of the notes, the value of the notes would likely be lower if the term of the notes is at the longer end of the determination date range, rather than the shorter end of the determination date range.

Although the Notes Provide For the Repayment of the Stated Principal Amount at Maturity, You May Nevertheless Suffer a Loss on Your Investment in Real Value Terms if the Underlier Appreciates, Declines Significantly From the Initial Underlier Level to the Final Underlier Level or if the Notes Are Automatically Called

This is because inflation may cause the real value of the stated principal amount to be less at maturity than it is at the time you invest, and because an investment in the notes represents a forgone opportunity to invest in an alternative asset that does generate a positive real return. This potential loss in real value terms is significant given the term of the notes. You should carefully consider whether an investment that may not provide for any return on your investment, or may provide a return that is lower than the return on alternative investments, is appropriate for you.

Investing in the Notes Is Not Equivalent to Investing in the Underlier or the Stocks that Constitute the Underlier

You will not have voting rights, rights to receive dividends or other distributions or any other rights with respect to the stocks that constitute the underlier.

The Notes Are Subject to the Credit Risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc.

If we default on our obligations under the notes and Citigroup Inc. defaults on its guarantee obligations, you may not receive anything owed to you under the notes.

The Notes Will Not Be Listed on Any Securities Exchange and You May Not Be Able to Sell Them Prior to Maturity

The notes will not be listed on any securities exchange. Therefore, there may be little or no secondary market for the notes. CGMI currently intends to make a secondary market in relation to the notes and to provide an indicative bid price for the notes on a daily basis. Any indicative bid price for the notes provided by CGMI will be determined in CGMI’s sole discretion, taking into account prevailing market conditions and other relevant factors, and will not be a representation by CGMI that the notes can be sold at that price, or at all. CGMI may suspend or terminate making a market and providing indicative bid prices without notice, at any time and for any reason. If CGMI suspends or terminates making a market, there may be no secondary market at all for the notes because it is likely that CGMI will be the only broker-dealer that is willing to buy your notes prior to maturity. Accordingly, an investor must be prepared to hold the notes until maturity.

Sale of the Notes Prior to Maturity May Result in a Loss of Principal

You will be entitled to receive at least the full stated principal amount of your notes, subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc., only if you hold the notes to maturity. The value of the notes may fluctuate during the term of the notes, and if you are able to sell your notes prior to maturity, you may receive less than the full stated principal amount of your notes.

The Estimated Value of the Notes on the Trade Date, Based on CGMI’s Proprietary Pricing Models and Our Internal Funding Rate, Will Be Less than the Issue Price

The difference is attributable to certain costs associated with selling, structuring and hedging the notes that are included in the issue price. These costs include (i) the selling concessions paid in connection with the offering of the notes, (ii) hedging and other costs incurred by us and our affiliates in connection with the offering of the notes and (iii) the expected profit (which may be more or less than actual profit) to CGMI or other of our affiliates in connection with hedging our obligations under the notes. These costs also include a fee paid to iCapital Markets LLC, an electronic

platform in which an affiliate of Goldman Sachs & Co. LLC, who is acting as a dealer in connection with the distribution of the notes, holds an indirect minority equity interest, for services it is providing in connection with this offering. These costs adversely affect the economic terms of the notes because, if they were lower, the economic terms of the notes would be more favorable to you. The economic terms of the notes are also likely to be adversely affected by the use of our internal funding rate, rather than our secondary market rate, to price the notes. See “The Estimated Value of the Notes Would Be Lower if It Were Calculated Based on Our Secondary Market Rate” below.

The Estimated Value of the Notes Was Determined for Us by Our Affiliate Using Proprietary Pricing Models

CGMI derived the estimated value disclosed on the cover page of this pricing supplement from its proprietary pricing models. In doing so, it may have made discretionary judgments about the inputs to its models, such as the volatility of the underlier, dividend yields on the stocks that constitute the underlier and interest rates. CGMI’s views on these inputs may differ from your or others’ views, and as an underwriter in this offering, CGMI’s interests may conflict with yours. Both the models and the inputs to the models may prove to be wrong and therefore not an accurate reflection of the value of the notes. Moreover, the estimated value of the notes set forth on the cover page of this pricing supplement may differ from the value that we or our affiliates may determine for the notes for other purposes, including for accounting purposes. You should not invest in the notes because of the estimated value of the notes. Instead, you should be willing to hold the notes to maturity irrespective of the initial estimated value.

The Estimated Value of the Notes Would Be Lower if It Were Calculated Based on Our Secondary Market Rate

The estimated value of the notes included in this pricing supplement is calculated based on our internal funding rate, which is the rate at which we are willing to borrow funds through the issuance of the notes. Our internal funding rate is generally lower than our secondary market rate, which is the rate that CGMI will use in determining the value of the notes for purposes of any purchases of the notes from you in the secondary market. If the estimated value included in this pricing supplement were based on our secondary market rate, rather than our internal funding rate, it would likely be lower. We determine our internal funding rate based on factors such as the costs associated with the notes, which are generally higher than the costs associated with conventional debt securities, and our liquidity needs and preferences. Our internal funding rate is not an interest rate that we will pay to investors in the notes, which do not bear interest.

Because there is not an active market for traded instruments referencing our outstanding debt obligations, CGMI determines our secondary market rate based on the market price of traded instruments referencing the debt obligations of Citigroup Inc., our parent company and the guarantor of all payments due on the notes, but subject to adjustments that CGMI makes in its sole discretion. As a result, our secondary market rate is not a market-determined measure of our creditworthiness, but rather reflects the market’s perception of our parent company’s creditworthiness as adjusted for discretionary factors such as CGMI’s preferences with respect to purchasing the notes prior to maturity.

The Estimated Value of the Notes Is Not an Indication of the Price, if Any, at Which CGMI or Any Other Person May Be Willing to Buy the Notes From You in the Secondary Market

Any such secondary market price will fluctuate over the term of the notes based on the market and other factors described in the next risk factor. Moreover, unlike the estimated value included in this pricing supplement, any value of the notes determined for purposes of a secondary market transaction will be based on our secondary market rate, which will likely result in a lower value for the notes than if our internal funding rate were used. In addition, any secondary market price for the notes will be reduced by a bid-ask spread, which may vary depending on the aggregate stated principal amount of the notes to be purchased in the secondary market transaction, and the expected cost of unwinding related hedging transactions. As a result, it is likely that any secondary market price for the notes will be less than the issue price.

The Value of the Notes Prior to Maturity Will Fluctuate Based on Many Unpredictable Factors

The value of your notes prior to maturity will fluctuate based on the level and volatility of the underlier and a number of other factors, including the price and volatility of the stocks that constitute the underlier, the dividend yields on the stocks that constitute the underlier, interest rates generally, the time remaining to maturity and our and Citigroup Inc.’s creditworthiness, as reflected in our secondary market rate. Changes in the level of the underlier may not result in a comparable change in the value of your notes. You should understand that the value of your notes at any time prior to maturity may be significantly less than the issue price.

If the Level of the Underlier Changes, the Market Value of Your Notes May Not Change in the Same Manner

Your notes may trade quite differently from the performance of the underlier. Changes in the level of the underlier may not result in a comparable change in the market value of your notes. We discuss some of the reasons for this disparity under “— The Value of the Notes Prior to Maturity Will Fluctuate Based on Many Unpredictable Factors” above.

Immediately Following Issuance, Any Secondary Market Bid Price Provided by CGMI, and the Value That Will Be Indicated on Any Brokerage Account Statements Prepared by CGMI or Its Affiliates, Will Reflect a Temporary Upward Adjustment

The amount of this temporary upward adjustment will steadily decline to zero over the temporary adjustment period. See “Valuation of the Notes” in this pricing supplement.

Our Offering of the Notes Does Not Constitute a Recommendation of a Bearish Position With Respect To the Underlier

The fact that we are offering the notes does not mean that we believe that investing in an instrument providing bearish exposure to the underlier is likely to achieve favorable returns. In fact, as we are part of a global financial institution, our affiliates may have positions (including long and short positions) in the stocks that constitute the underlier or in instruments related to the underlier or such stocks and may publish research or express opinions, that in each case are inconsistent with an investment linked to the underlier. These and other activities of our affiliates may affect the level of the underlier in a way that has a negative impact on your interests as a holder of the notes.

The Level of the Underlier May Be Adversely Affected by Our or Our Affiliates’ Hedging and Other Trading Activities

We expect to hedge our obligations under the notes through CGMI or other of our affiliates, or through a dealer participating in this offering or its affiliates, who may take positions directly in the stocks that constitute the underlier and other financial instruments related to the underlier or such stocks and may adjust such positions during the term of the notes. Our affiliates also trade the stocks that constitute the underlier and other financial instruments related to the underlier or such stocks on a regular basis (taking long or short positions or both), for their accounts, for other accounts under their management or to facilitate transactions on behalf of customers. Any dealer participating in the offering of the notes or its affiliates may engage in similar activities. These activities could affect the level of the underlier in a way that negatively affects the value of the notes. They could also result in substantial returns for us or our affiliates or any dealer or its affiliates while the value of the notes declines. If the dealer from which you purchase notes is to conduct hedging activities for us in connection with the notes, that dealer may profit in connection with such hedging activities and such profit, if any, will be in addition to the compensation that the dealer receives for the sale of the notes to you. You should be aware that the potential to earn fees in connection with hedging activities may create a further incentive for the dealer to sell the notes to you in addition to the compensation they would receive for the sale of the notes.

We and Our Affiliates May Have Economic Interests That Are Adverse to Yours as a Result of Our Affiliates’ Business Activities

Our affiliates may currently or from time to time engage in business with the issuers of the stocks that constitute the underlier, including extending loans to, making equity investments in or providing advisory services to such issuers. In the course of this business, we or our affiliates may acquire non-public information about such issuers, which we will not disclose to you. Moreover, if any of our affiliates is or becomes a creditor of any such issuer, they may exercise any remedies against such issuer that are available to them without regard to your interests. Any dealer participating in the offering of the notes or its affiliates may engage in similar activities.

The Calculation Agent, Which Is an Affiliate of Ours, Will Make Important Determinations With Respect to the Notes

If certain events occur, such as market disruption events or the discontinuance of the underlier, CGMI, as calculation agent, will be required to make discretionary judgments that could significantly affect your payment at maturity. In making these judgments, the calculation agent’s interests as an affiliate of ours could be adverse to your interests as a holder of the notes.

Adjustments to the Underlier May Affect the Value of Your Notes

The underlier sponsor may add, delete or substitute the stocks that constitute the underlier or make other methodological changes that could affect the level of the underlier. The underlier sponsor may discontinue or suspend calculation or publication of the underlier at any time without regard to your interests as holders of the notes.

We May Sell an Additional Aggregate Stated Principal Amount of the Notes at a Different Issue Price

At our sole option, we may decide to sell an additional aggregate stated principal amount of the notes subsequent to the date of this pricing supplement. The issue price of the notes in the subsequent sale may differ substantially (higher or lower) from the original issue price you paid as provided on the cover of this pricing supplement.

If You Purchase Your Notes at a Premium to the Stated Principal Amount, the Return on Your Investment Will Be Lower Than the Return on Notes Purchased at the Stated Principal Amount and the Impact of Certain Key Terms of the Notes Will Be Negatively Affected

The cash settlement amount will not be adjusted based on the issue price you pay for the notes. If you purchase notes at a price that differs from the stated principal amount of the notes, then the return on your investment in such notes held to a call payment date or the maturity date will differ from, and may be substantially less than, the return on notes purchased at the stated principal amount. If you purchase your notes at a premium to the stated principal amount and hold them to a call payment date or the maturity date, the return on your investment in the notes will be lower than it would have been had you purchased the notes at the stated principal amount or a discount to the stated principal amount.

THE UNDERLIER

The S&P 500^® Index consists of common stocks of 500 issuers selected to provide a performance benchmark for the large capitalization segment of the U.S. equity markets. The S&P 500^® Index is calculated and maintained by S&P Dow Jones Indices LLC. The S&P 500^® Index is reported by Bloomberg L.P. under the ticker symbol “SPX.”

“Standard & Poor’s,” “S&P” and “S&P 500^®” are trademarks of Standard & Poor’s Financial Services LLC and have been licensed for use by Citigroup Inc. and its affiliates. For more information, see “Equity Index Descriptions—The S&P U.S. Indices—License Agreement” in the accompanying underlying supplement.

Please refer to the section “Equity Index Descriptions—The S&P U.S. Indices” in the accompanying underlying supplement for additional information. Additional information is available on the underlier sponsor’s website (including information regarding (i) the underlier’s top ten constituents and (ii) the underlier’s sector weightings). We are not incorporating by reference the website or any material it includes in this document. Neither the issuer nor CGMI makes any representation that such publicly available information regarding the underlier is accurate or complete.

Historical Closing Levels of the Underlier

The closing level of the underlier has fluctuated in the past and may, in the future, experience significant fluctuations. Any historical upward or downward trend in the closing level of the underlier during the period shown below is not an indication that the underlier is more or less likely to increase or decrease at any time during the life of your notes.

You should not take the historical levels of the underlier as an indication of the future performance of the underlier. We cannot give you any assurance that the future performance of the underlier will result in your receiving an amount greater than the stated principal amount of your notes on the maturity date.

Neither we nor any of our affiliates make any representation to you as to the performance of the underlier. The actual performance of the underlier over the life of the notes, as well as the cash settlement amount, may bear little relation to the historical levels shown below.

The graph below shows the closing level of the underlier for each day such level was available from January 2, 2019 to May 8, 2024. We obtained the closing levels from Bloomberg L.P., without independent verification.

The closing level of the underlier on May 8, 2024 was 5,187.67.

UNITED STATES FEDERAL TAX CONSIDERATIONS

In the opinion of our counsel, Davis Polk & Wardwell LLP, which is based on current market conditions, the notes should be treated as “short-term debt instruments” for U.S. federal income tax purposes, as described in the section of the accompanying product supplement called “United States Federal Tax Considerations—Short Term Notes,” and the remaining discussion is based on this treatment.

Under the rules applicable to short-term debt instruments, if you are a cash-method U.S. Holder, you generally should not be required to recognize income with respect to the notes until maturity or an earlier disposition. If you are an accrual-method U.S. Holder (or a cash-method U.S. Holder who elects to accrue income currently on short-term debt instruments), you are required to accrue original issue discount into income over the term of the notes; however, because the amount of the payment at maturity is contingent, the amount required to be included in income is uncertain.

Upon the sale, exchange or retirement of the notes (including retirement at maturity), you generally will recognize gain or loss equal to the difference between the proceeds received and your adjusted tax basis in the notes. Your adjusted tax basis will equal your purchase price for the notes, increased, if you accrue income on the notes currently, by any previously accrued but unpaid discount. Any loss recognized should be treated as short-term capital loss and any gain recognized at maturity should be treated as ordinary income. If you dispose of a note prior to maturity at a gain, you should consult your tax adviser regarding the determination of the amount of such gain that is treated as ordinary income and the amount that is treated as short-term capital gain.

You should read the section entitled “United States Federal Tax Considerations—Short Term Notes” in the accompanying product supplement. You should also consult your tax adviser regarding the U.S. federal tax consequences of an investment in the notes.

Non-U.S. Holders. Subject to the discussions below regarding Section 871(m) and in “United States Federal Tax Considerations—Tax Consequences to Non-U.S. Holders” and “—FATCA” in the accompanying product supplement, if you are a Non-U.S. Holder (as defined in the accompanying product supplement) of the notes, under current law you generally will not be subject to U.S. federal withholding or income tax in respect of any payment on or any amount received on the sale, exchange or retirement of the notes, provided that (i) income in respect of the notes is not effectively connected with your conduct of a trade or business in the United States, and (ii) you comply with the applicable certification requirements. See “United States Federal Tax Considerations—Tax Consequences to Non-U.S. Holders” in the accompanying product supplement for a more detailed discussion of the rules applicable to Non-U.S. Holders of the notes.

As discussed under “United States Federal Tax Considerations—Tax Consequences to Non-U.S. Holders—Dividend Equivalents Under Section 871(m) of the Code” in the accompanying product supplement, Section 871(m) of the Internal Revenue Code of 1986, as amended, and Treasury regulations promulgated thereunder (“Section 871(m)”) generally impose a 30% withholding tax on dividend equivalents paid or deemed paid to Non-U.S. Holders with respect to certain financial instruments linked to U.S. equities (“Underlying Securities”) or indices that include Underlying Securities. Section 871(m) generally applies to instruments that substantially replicate the economic performance of one or more Underlying Securities, as determined based on tests set forth in the applicable Treasury regulations. However, the regulations, as modified by an Internal Revenue Service (“IRS”) notice, exempt financial instruments issued prior to January 1, 2025 that do not have a “delta” of one. Based on the terms of the notes and representations provided by us as of the date of this preliminary pricing supplement, our counsel is of the opinion that the notes should not be treated as transactions that have a “delta” of one within the meaning of the regulations with respect to any Underlying Security and, therefore, should not be subject to withholding tax under Section 871(m). However, the final determination regarding the treatment of the notes under Section 871(m) will be made as of the pricing date for the notes, and it is possible that the notes will be subject to withholding under Section 871(m) based on the circumstances as of that date.

A determination that the notes are not subject to Section 871(m) is not binding on the IRS, and the IRS may disagree with this treatment. Moreover, Section 871(m) is complex and its application may depend on your particular circumstances, including your other transactions. You should consult your tax adviser regarding the potential application of Section 871(m) to the notes.

If withholding tax applies to the notes, we will not be required to pay any additional amounts with respect to amounts withheld.

You should read the section entitled “United States Federal Tax Considerations” in the accompanying product supplement. The preceding discussion, when read in combination with that section, constitutes the full opinion of Davis Polk & Wardwell LLP regarding the material U.S. federal tax consequences of owning and disposing of the notes.

You should also consult your tax adviser regarding all aspects of the U.S. federal tax consequences of an investment in the notes and any tax consequences arising under the laws of any state, local or non-U.S. taxing jurisdiction.

VALUATION OF THE NOTES

CGMI calculated the estimated value of the notes set forth on the cover page of this pricing supplement based on proprietary pricing models. CGMI’s proprietary pricing models generated an estimated value for the notes by estimating the value of a hypothetical package of financial instruments that would replicate the payout on the notes, which consists of a fixed-income bond (the “bond component”) and one or more derivative instruments underlying the economic terms of the notes (the “derivative component”). CGMI calculated the estimated value of the bond component using a discount rate based on our internal funding rate. CGMI calculated the estimated value of the derivative component based on a proprietary derivative-pricing model, which generated a theoretical price for the instruments that constitute the derivative component based on various inputs, including the factors described under “Summary Risk Factors—The Value of the Notes Prior to Maturity Will Fluctuate Based on Many Unpredictable Factors” in this pricing supplement, but not including our or Citigroup Inc.’s creditworthiness. These inputs may be market-observable or may be based on assumptions made by CGMI in its discretionary judgment.

The estimated value of the notes is a function of the terms of the notes and the inputs to CGMI’s proprietary pricing models. The range for the estimated value of the notes set forth on the cover page of this preliminary pricing supplement reflects terms of the notes that have not yet been fixed as well as uncertainty on the date of this preliminary pricing supplement about the inputs to CGMI’s proprietary pricing models on the trade date.

For a period of approximately three months following issuance of the notes, the price, if any, at which CGMI would be willing to buy the notes from investors, and the value that will be indicated for the notes on any brokerage account statements prepared by CGMI or its affiliates (which value CGMI may also publish through one or more financial information vendors), will reflect a temporary upward adjustment from the price or value that would otherwise be determined. This temporary upward adjustment represents a portion of the hedging profit expected to be realized by CGMI or its affiliates over the term of the notes. The amount of this temporary upward adjustment will decline to zero on a straight-line basis over the three-month temporary adjustment period. However, CGMI is not obligated to buy the notes from investors at any time. See “Summary Risk Factors — The Notes Will Not Be Listed on Any Securities Exchange and You May Not Be Able to Sell Them Prior to Maturity.”

© 2024 Citigroup Global Markets Inc. All rights reserved. Citi and Citi and Arc Design are trademarks and service marks of Citigroup Inc. or its affiliates and are used and registered throughout the world.