Issuer:

Citigroup Global Markets Holdings Inc.

Guarantor:

Citigroup Inc.

Underlying:

The S&P 500 Futures 35% Edge Volatility 6% Decrement Index (USD) ER (ticker: “SPXF3EV6”) (the “Index”)

Pricing date:

August 27, 2025

Valuation dates:

Quarterly, beginning approximately one year after issuance

Final valuation date:

August 29, 2035

Maturity date:

September 4, 2035

Final barrier value:

50.00% of the initial underlying value

Automatic early redemption:

If on any valuation date prior to the final valuation date the closing value of the underlying is greater than or equal to the initial underlying value, the securities will be automatically called for an amount equal to the principal plus the applicable premium

Premium:

20.80% per annum

CUSIP / ISIN:

17333MEF6 / US17333MEF68

Initial underlying value:

The closing value on the pricing date

Final underlying value:

The closing value on the final valuation date

Underlying return:

(Final underlying value - initial underlying value) / initial underlying value

Payment at maturity (if not autocalled):

•If the final underlying value is greater than or equal to the initial underlying value:

$1,000 + the premium applicable to the final valuation date

•If the final underlying value is less than the initial underlying value but greater than or equal to the final barrier value:

$1,000

•If the final underlying value is less than the final barrier value:

$1,000 + ($1,000 × the underlying return)

If the securities are not automatically redeemed prior to maturity and the final underlying value is less than the final barrier value, you will receive significantly less than the stated principal amount of your securities, and possibly nothing, at maturity.

All payments on the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc.

Stated principal amount:

$1,000 per security

Preliminary pricing supplement:

Preliminary Pricing Supplement dated August 13, 2025

Valuation Date on which the Closing Value of the Underlying Equals or Exceeds Initial Underlying Value

Premium

Hypothetical Redemption

August 31, 2026

20.80%

$1,208.00

November 30, 2026

26.00%

$1,260.00

March 1, 2027

31.20%

$1,312.00

June 1, 2027

36.40%

$1,364.00

August 30, 2027

41.60%

$1,416.00

November 29, 2027

46.80%

$1,468.00

February 29, 2028

52.00%

$1,520.00

May 30, 2028

57.20%

$1,572.00

August 29, 2028

62.40%

$1,624.00

November 29, 2028

67.60%

$1,676.00

February 28, 2029

72.80%

$1,728.00

May 29, 2029

78.00%

$1,780.00

August 29, 2029

83.20%

$1,832.00

November 29, 2029

88.40%

$1,884.00

February 28, 2030

93.60%

$1,936.00

May 29, 2030

98.80%

$1,988.00

August 29, 2030

104.00%

$2,040.00

November 29, 2030

109.20%

$2,092.00

February 28, 2031

114.40%

$2,144.00

May 29, 2031

119.60%

$2,196.00

August 29, 2031

124.80%

$2,248.00

December 1, 2031

130.00%

$2,300.00

March 1, 2032

135.20%

$2,352.00

June 1, 2032

140.40%

$2,404.00

August 30, 2032

145.60%

$2,456.00

November 29, 2032

150.80%

$2,508.00

February 28, 2033

156.00%

$2,560.00

May 31, 2033

161.20%

$2,612.00

August 29, 2033

166.40%

$2,664.00

November 29, 2033

171.60%

$2,716.00

February 28, 2034

176.80%

$2,768.00

May 30, 2034

182.00%

$2,820.00

August 29, 2034

187.20%

$2,872.00

November 29, 2034

192.40%

$2,924.00

February 28, 2035

197.60%

$2,976.00

May 29, 2035

202.80%

$3,028.00

Hypothetical Underlying Return on Final Valuation Date

Hypothetical Payment at Maturity

100.00%

$3,080.00

50.00%

$3,080.00

25.00%

$3,080.00

0.00%

$3,080.00

-0.01%

$1,000.00

-25.00%

$1,000.00

-50.00%

$1,000.00

-50.01%

$499.90

-75.00%

$250.00

-100.00%

$0.00

Additional Information

Citigroup Global Markets Holdings Inc. and Citigroup Inc. have filed registration statements (including the accompanying preliminary pricing supplement, product supplement, underlying supplement, prospectus supplement and prospectus) with the Securities and Exchange Commission (“SEC”) for the offering to which this communication relates. Before you invest, you should read the accompanying preliminary pricing supplement, product supplement, underlying supplement, prospectus supplement and prospectus in those registration statements (File Nos. 333-270327 and 333-270327-01) and the other documents Citigroup Global Markets Holdings Inc. and Citigroup Inc. have filed with the SEC for more complete information about Citigroup Global Markets Holdings Inc., Citigroup Inc. and this offering. You may obtain these documents without cost by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, you can request these documents by calling toll-free 1-800-831-9146.

Filed pursuant to Rule 433

This offering summary does not contain all of the material information an investor should consider before investing in the securities. This offering summary is not for distribution in isolation and must be read together with the accompanying preliminary pricing supplement and the other documents referred to therein, which can be accessed via the link on the first page.

Selected Risk Considerations

•You may lose a significant portion or all of your investment. Unlike conventional debt securities, the securities do not provide for the repayment of the stated principal amount at maturity in all circumstances. If the securities are not automatically redeemed prior to maturity, your payment at maturity will depend on the final underlying value. If the final underlying value is less than the final barrier value, you will lose 1% of the stated principal amount of your securities for every 1% by which the underlying has declined from the initial underlying value. There is no minimum payment at maturity on the securities, and you may lose up to all of your investment.

•Your potential return on the securities is limited.

•The securities do not pay interest.

•You will not receive dividends or have any other rights with respect to the underlying.

•The securities may be automatically redeemed prior to maturity.

•The securities offer downside exposure, but no upside exposure, to the underlying.

•The securities are particularly sensitive to the volatility of the closing value of the underlying on or near the valuation dates.

•The securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc. If Citigroup Global Markets Holdings Inc. defaults on its obligations under the securities and Citigroup Inc. defaults on its guarantee obligations, you may not receive anything owed to you under the securities.

•The securities will not be listed on any securities exchange and you may not be able to sell them prior to maturity.

•The estimated value of the securities on the pricing date will be less than the issue price. For more information about the estimated value of the securities, see the accompanying preliminary pricing supplement.

•The value of the securities prior to maturity will fluctuate based on many unpredictable factors.

•The issuer and its affiliates may have conflicts of interest with you.

•The U.S. federal tax consequences of an investment in the securities are unclear.

•The Index is highly risky because it may reflect highly leveraged exposure to the Underlying Futures Index and may therefore experience a decline that is many multiples of any decline in the Underlying Futures Index.

•The Index may realize significant losses if it is not consistently successful in increasing exposure to the Underlying Futures Index in advance of increases in the Underlying Futures Index and reducing exposure to the Underlying Futures Index in advance of declines in the Underlying Futures Index.

•The Index may be adversely affected by a time lag in its volatility targeting mechanism.

•The Index may be adversely affected by a “decay” effect.

•The Underlying Futures Index is expected to underperform the S&P 500^® Index because of an implicit financing cost.

•The performance of the Index will be reduced by a decrement of 6% per annum.

•The Index may not fully participate in any appreciation of the Underlying Futures Index.

•The Index may perform less favorably than it would if its volatility targeting mechanism were based on an alternative volatility measure, such as actual realized volatility, rather than implied volatility.

•The Index may significantly underperform the S&P 500^® Index.

•The Index has limited actual performance information.

•An affiliate of ours participated in the development of the Index.

The above summary of selected risks does not describe all of the risks associated with an investment in the securities. You should read the accompanying preliminary pricing supplement and product supplement for a more complete description of risks relating to the securities.