Fiscal Year 2026 Issuances

On July 18, 2025, the Company issued and sold 13,850,000 Common Shares, at an offering price of $3.25 per Common Share, in a registered offering (the “July 2025 Offering”) under the Company’s registration statement on Form S-3 (Registration No. 333-280176), pursuant to the Placement Agency Agreement between the Company and Maxim Group LLC (“Maxim”), dated July 17, 2025. The Company received net proceeds from the July 2025 Offering, after deducting placement agent fees and other offering expenses payable by the Company, of approximately $41,335.

On September 19, 2025, the Company issued and sold 10,000,000 Common Shares, at an offering price of $5.00 per Common Share, in a registered direct offering (the “September 2025 Registered Direct Offering”) under the Company’s registration statement on Form S-3 (Registration No. 333-280176), pursuant to the Placement Agency Agreement between the Company and Maxim, dated September 17, 2025. The Company received net proceeds from the September 2025 Registered Direct Offering, after deducting placement agent fees and other offering expenses payable by the Company, of approximately $46,048.

On September 29, 2025, the Company issued and sold (a) 7,004,740 Common Shares at a public offering price of $6.15 per Common Share and (b) 2,755,260 pre-funded Warrants to purchase an aggregate of 2,755,260 Common Shares (the “September Pre-Funded Warrants”) at a public offering price of $6.1499 per September Pre-Funded Warrant in a confidentially marketed public offering (the “September 2025 Public Offering”) under the Company’s registration statement on Form S-3 (Registration No. 333-280176), pursuant to the Placement Agency Agreement between the Company and Maxim, dated September 26, 2025. On September 30, 2025, the Company issued 2,755,218 Common Shares in connection with the cashless exercise of all of the outstanding September Pre-Funded Warrants. The Company received net proceeds from the September 2025 Public Offering, after deducting placement agent fees and other offering expenses payable by the Company, of approximately $55,365.

On October 15, 2025, the Company issued and sold (a) 10,152,175 Common Shares at an offering price of $9.34 per Common Share and (b) 5,925,000 pre-funded Warrants (the “October Pre-Funded Warrants”) to purchase up to an additional 5,925,000 Common Shares at an offering price of $9.3399 per October Pre-Funded Warrant in a registered offering (the “October 2025 Offering”) under the Company's registration statement on Form S-3 (Registration No. 333-290837), pursuant to the Placement Agency Agreement between the Company and Maxim, dated October 13, 2025. On October 17, 2025, the Company issued 5,924,942 Common Shares in connection with the cashless exercise of all of the outstanding October Pre-Funded Warrants. The Company received net proceeds from the October 2025 Offering, after deducting placement agent fees and other offering expenses payable by the Company, of approximately $138,974.

On February 25, 2026, the Company issued and sold (a) 17,400,000 Common Shares at an offering price of $5.00 per Common Share and (b) 2,600,000 pre-funded Warrants (the “February Pre-Funded Warrants”) to purchase up to an additional 2,600,000 Common Shares at an offering price of $4.9999 per February Pre-Funded Warrant in a registered offering (the “February 2026 Offering”) under the Company's registration statement on Form S-3 (Registration No. 333-290837), pursuant to the Placement Agency Agreement between the Company and Maxim, dated February 24, 2026. On February 25, 2026 and March 4, 2026, the Company issued a total of 2,599,951 Common Shares in connection with the cashless exercise of all of the outstanding February Pre-Funded Warrants. The Company received net proceeds from the February 2026 Offering, after deducting placement agent fees and other offering expenses payable by the Company, of approximately $93,406.

Fiscal Year 2025 Issuances

On November 5, 2024, the Company closed an underwritten public offering (the “November 2024 Registered Offering”), pursuant to the underwriting agreement, dated November 3, 2024 (the “November 2024 Underwriting Agreement”), with Maxim, as underwriter, which consisted of 1,592,356 Common Shares, 1,672,090 Warrants (the “Series A Public Warrants”) to purchase up to an additional 1,672,090 Common Shares and 836,045 Warrants (the “Series B Public Warrants” and, together with the Series A Public Warrants, the “November 2024 Public Warrants”) to purchase up to an additional 836,045 Common Shares. Each Common Share was sold together with one Series A Public Warrant and one-half of one Series B Public Warrant at a combined public offering price of $1.57. The gross proceeds from the November 2024 Registered Offering were $2,501 before deducting underwriting discounts and offering expenses. The November 2024 Public Warrants were classified as equity instruments and accordingly, the net proceeds were allocated based on the relative fair values of the Common Shares and the November 2024 Public Warrants on the date of issuance, with $943 allocated to the fair value of the November 2024 Public Warrants and the balance of the proceeds of $1,558 allocated to Common Shares. The Company incurred total transaction costs related to the November 2024 Registered Offering of $1,226, which were treated as share issuance costs at closing. The Series A Public Warrants have an exercise price of $1.75 per underlying Common Share, are exercisable immediately, and will expire on November 5, 2026. The Series B Public Warrants have an exercise price of $2.07 per underlying Common Share, are exercisable beginning six months and one day from the date of issuance and will expire on November 5, 2029. In addition, pursuant to the November 2024 Underwriting Agreement, the Company granted Maxim a 45-day over-allotment option to purchase (i) 238,853 additional Common Shares and (ii) 358,280 Option Warrants (as defined below) to purchase up to an aggregate of 358,280 Common Shares. “Option Warrant” means one Series A Public Warrant combined with one-half of one Series B Public Warrant. On November 4, 2024, Maxim partially exercised its over-allotment option to purchase 79,734 additional Series A Public Warrants and 39,867 additional Series B Public Warrants, which amounts are included in the amounts discussed above and were issued at closing of the November 2024 Registered Offering.

On November 13, 2024, the Company closed a non-brokered private placement (the “November 2024 Private Offering”), pursuant to binding subscription agreements with certain accredited investors as part of a non-brokered private placement of 2,199,602 units of the Company (the “November 2024 Units”). Each November 2024 Unit consisted of one Common Share, one Warrant (a “Series A Private Warrant”) to purchase one Common Share, and one-half of one Warrant (each whole such Warrant, a “Series B Private Warrant” and, together with the Series A Private Warrants, the “November 2024 Private Warrants”), with each Series B Private Warrant entitling the holder thereof to purchase one additional Common Share. Each November 2024 Unit was issued and sold at a price of $1.57. The gross proceeds of the November 2024 Private Offering were approximately $3,500 before deducting offering expenses. Certain directors and officers of the Company (the “Insider Investors”) purchased November 2024 Units at a price of $1.7675 per November 2024 Unit, which price includes $0.1975 per November 2024 Private Warrant and allowed such directors and officers to participate in the November 2024 Private Offering in accordance with the rules of the Nasdaq. The Series A Private Warrants have an exercise price of $1.75 per underlying Common Share, are exercisable immediately, and will expire on November 13, 2026. The Series B Private Warrants have an exercise price of $2.07 per underlying Common Share, are exercisable beginning six months and one day from the date of issuance and will expire on November 13, 2029. The Company recorded a non-cash expense of $34 and $110 to other operating expenses and employee related costs, respectively, representing the excess of fair value of the November 2024 Units over the purchase price paid by Insider Investors.

Based upon the Company’s analysis of the criteria contained in ASC 815, the Company determined that the November 2024 Private Warrants met the definition of a derivative liability, as any Warrant exercise that could

cause the holder to exceed 19.9% ownership of NioCorp Common Shares would require shareholder approval. As such, the November 2024 Private Warrants were recognized as warrant liabilities on the consolidated balance sheet and were measured at their issuance date fair value of $1,928 and subsequently remeasured at each reporting period with changes being recorded as a non-operating gain or loss in the consolidated statement of operations and comprehensive loss. The remaining proceeds of the November 2024 Private Offering of $1,573 were allocated to Common Shares. The Company incurred total transaction costs related to the November 2024 Private Offering of $161, of which $60 was allocated to the November 2024 Private Warrants and was expensed at closing.

On January 31, 2025, the Company closed an underwritten registered direct offering (the “January 2025 Offering”), pursuant to an underwriting agreement, dated January 29, 2025, with Maxim, as underwriter, pursuant to which the Company issued and sold 2,577,320 Common Shares, 2,577,320 Series A Warrants to purchase up to 2,577,320 Common Shares (the “January 2025 Series A Warrants”) and 1,288,660 Series B Warrants to purchase up to an additional 1,288,660 Common Shares (the “January 2025 Series B Warrants” and, together with the January 2025 Series A Warrants, the “January 2025 Warrants”). Each Common Share was sold together with one January 2025 Series A Warrant and one-half of one January 2025 Series B Warrant at a combined public offering price of $1.94. The gross proceeds from the January 2025 Offering were approximately $5,000 before deducting underwriting discounts and offering expenses. The January 2025 Warrants were classified as equity instruments, and accordingly, the net proceeds were allocated based on the relative fair values of the Common Shares and the January 2025 Warrants on the date of issuance, with $2,200 allocated to the fair value of the January 2025 Warrants and the balance of the proceeds of $2,800 allocated to Common Shares. The Company incurred total transaction costs related to the January 2025 Offering of $799, which were treated as share issuance costs at closing. The January

On April 21, 2025, the Company closed an underwritten public offering (the “April 2025 Offering”), pursuant to an underwriting agreement, dated April 17, 2025, with Maxim, as underwriter, pursuant to which the Company issued and sold (i) 6,628,846 Common Shares at a public offering price of $2.60 per Common Share and (ii) 1,063,462 pre-funded Warrants (the “April 2025 Pre-Funded Warrants”) to purchase up to an additional 1,063,462 Common Shares at a public offering price of $2.5999. The April 2025 Pre-Funded Warrants have an exercise price of $0.0001 per underlying Common Share, are exercisable immediately, and do not have an expiration date. On April 17, 2025, Maxim partially exercised its over-allotment option to purchase 323,504 additional Common Shares at closing. The gross proceeds from the April 2025 Offering were approximately $20,841 before deducting underwriting discounts and offering expenses. The April 2025 Pre-Funded Warrants were classified as equity instruments and accordingly, the net proceeds were allocated based on the relative fair values of the Common Shares and the April 2025 Pre-Funded Warrants on the date of issuance, with $2,765 allocated to the fair value of the April 2025 Pre-Funded Warrants (based on the value of the underlying Common Shares at closing) and the balance of the proceeds of $18,076 allocated to Common Shares. The Company incurred total transaction costs related to the April 2025 Offering of $2,102, which were treated as share issuance costs at closing.

Yorkville Equity Facility Financing Agreement Issuances

The Company entered into a Standby Equity Purchase Agreement, dated January 26, 2023 (the “Yorkville Equity Facility Financing Agreement”) between the Company and YA II PN, Ltd., an investment fund managed by Yorkville Advisors Global, LP (“Yorkville”) which expired on April 1, 2026. The Company issued the following Common Shares under the Yorkville Equity Facility Financing Agreement during the periods presented below:

On April 6, 2026, the Company’s shareholders voted to approve an amendment and restatement of its long-term incentive plan, the NioCorp Developments Ltd. Long Term Incentive Plan (as amended, the “2017 Amended Long-Term Incentive Plan”). Under the 2017 Amended Long-Term Incentive Plan, the Board may, in its discretion from time to time, grant Options and share units (in the form of restricted share units and performance share units), plus dividend equivalents, to non-employee directors, employees and certain other service providers (as described in the 2017 Amended Long-Term Incentive Plan) of the Company and affiliated entities selected by the Board.

Subject to adjustment as described in the 2017 Amended Long-Term Incentive Plan, and subject to the plan's share counting rules, the aggregate number of Common Shares available for awards under the 2017 Amended Long-Term Incentive Plan may not exceed 11,300,000 Common Shares, minus, as of April 5, 2026, one Common Share for every one Common Share subject to an award granted under the 2017 Amended Long-Term Incentive Plan after February 9, 2026 and before April 6, 2026. The 2017 Amended Long-Term Incentive Plan also limits the maximum annual compensation that may be granted to our non-employee directors for service on the Board to $750 (measured as described in the plan document), subject to exceptions for distributions of previously deferred compensation for services as an executive officer or employee, and non-preferential dividends or dividend equivalents.

The Board has power over the granting, amendment, administration, or settlement of any award.

As of June 30, 2026, 53.3% of the outstanding Options were fully vested. The total intrinsic value of Options exercised during the year ended June 30, 2026 was $1,654, and as of June 30, 2026, there was $1,540 of unrecognized compensation costs related to unvested share-based compensation arrangements granted. The Company recognized share-based compensation expense of $4,441 and $789 for the years ended June 30, 2026 and 2025, respectively.

Warrant transactions are summarized as follows. Weighted average exercise prices related to Canadian dollar denominated Warrants were converted to U.S. dollars using end of period foreign currency exchange rates.

In connection with the Closing, pursuant to the Business Combination Agreement, the Company assumed GXII’s obligations under the agreement (the “GXII Warrant Agreement”) governing the GXII share purchase Warrants (the “GXII Warrants”) and each GXII Warrant thereunder that was issued and outstanding immediately prior to the Closing Date was converted into one Warrant to purchase 1.11829212 Common Shares (the “NioCorp Assumed Warrants”) pursuant to the GXII Warrant Agreement, as amended by an Assignment, Assumption and Amendment Agreement, dated March 17, 2023, among the Company, GXII, Continental Stock Transfer & Trust Company, as the existing warrant agent, and Computershare Inc. and its affiliate, Computershare Trust Company, N.A, together as the successor warrant agent (the “NioCorp Assumed Warrant Agreement”). In connection with the Closing, NioCorp issued (a) 9,999,959 public NioCorp Assumed Warrants (the “2023 Public Warrants”) in respect of the GXII Warrants that were publicly traded prior to the Closing and (b) 5,666,667 NioCorp Assumed Warrants (the “2023 Private Warrants”) to the Sponsor in respect of the GXII Warrants that it held prior to the Closing, which NioCorp Assumed Warrants were subsequently distributed by the Sponsor to its members in connection with the Closing.

Each NioCorp Assumed Warrant entitles the holder to the right to purchase 1.11829212 Common Shares at an exercise price of $11.50 per 1.11829212 Common Shares (subject to adjustments for stock splits, stock dividends, reorganizations, recapitalizations and the like). No fractional shares will be issued upon exercise of any NioCorp Assumed Warrants, and fractional shares that would otherwise be due to the exercising holder will be rounded down to the nearest whole Common Share. In no event will the Company be required to net cash settle any NioCorp Assumed Warrant.

2023 Public Warrants

The Company may elect to redeem the 2023 Public Warrants subject to certain conditions, in whole and not in part, at a price of $0.01 per 2023 Public Warrant if (i) 30 days’ prior written notice of redemption is provided to the

holders, (ii) the last reported sale price of the Common Shares equals or exceeds approximately $16.10 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within a 30-trading day period ending on the third business day prior to the date on which the Company sends the notice of redemption to the Warrant holders and (iii) there is an effective registration statement covering the Common Shares issuable upon exercise of the 2023 Public Warrants, and a current prospectus relating thereto, available through the redemption date. Upon issuance of a redemption notice by the Company, the Warrant holders will have until the redemption date to exercise for cash, or, at the Company’s election, on a cashless basis.

2023 Private Warrants

The 2023 Private Warrants: (i) will be exercisable either for cash or on a cashless basis at the holder’s option and (ii) will not be redeemable by the Company, in either case as long as the 2023 Private Warrants are held by the initial purchasers or their permitted transferees. Any 2023 Private Warrants that are held by someone other than the initial purchasers or their permitted transferees are treated as 2023 Public Warrants.

The Company accounts for the 2023 Private Warrants in accordance with the guidance contained in ASC 815-40. Such guidance provides that because the 2023 Private Warrants do not meet the criteria for equity treatment thereunder, the 2023 Private Warrants must be recorded as a liability. This liability is carried as a component of Warrant liabilities on the consolidated balance sheet and is subject to re-measurement at each balance sheet date. With each such re-measurement, the warrant liability will be adjusted to its current fair value, with the change in fair value recognized in the consolidated statement of operations and comprehensive loss. The Company will reassess the classification at each balance sheet date.

As provided for in the NioCorp Assumed Warrant Agreement, through June 30, 2026, a total of 3,447,246 2023 Private Warrants were exchanged for 2023 Public Warrants. The Company recorded a non-cash loss of $1,217 and $26 for the years ending June 30, 2026 and 2025, respectively, in change in fair value of warrant liabilities in the consolidated statement of operations, representing the change in fair value of the 2023 Private Warrants through the respective exercise dates.

Contingent Consent Warrants

As consideration for entering into the previously publicly disclosed Waiver and Consent Agreement, dated September 25, 2022 (the “Lind Consent”), between the Company and Lind Global Asset Management III, LLC (“Lind III”), Lind III received, amongst other things, the right to receive additional Warrants (the “Contingent

On September 17, 2024, the Company’s Common Share price was below the threshold price set forth in the Lind Consent, and accordingly, the Company issued 2,816,742 Contingent Consent Warrants to Lind III. Each Contingent Consent Warrant is exercisable for one Common Share at an exercise price of $2.308 and may be exercised at any time prior to their expiration on September 17, 2028. The number of Contingent Consent Warrants issued was based on $5,000 divided by the five-day volume weighted average price of the Common Shares on September 16, 2024. The Company valued the Contingent Consent Warrants at $2,262 based on a Black-Scholes valuation with the following inputs:

The Company recognized a gain of $103 on the issuance of the Contingent Consent Warrants. This gain was recorded as a part of other non-operating expense (income) in the consolidated statements of operations and comprehensive loss.

April 2024 Warrants

As previously disclosed, on April 12, 2024, the Company issued and sold to Yorkville and Lind Global Fund II LP (together with Yorkville, the “April 2024 Purchasers”) $8,000 aggregate principal amount of unsecured notes (the “April 2024 Notes”), pursuant to a securities purchase agreement, dated April 11, 2024, between the Company and each of the April 2024 Purchasers. The Company also issued to the April 2024 Purchasers, in proportion to the aggregate principal amount of April 2024 Notes issued to each April 2024 Purchaser, Warrants (the “April 2024 Warrants”) to purchase up to 615,385 Common Shares, which are equal to 25% of the aggregate principal amount of April 2024 Notes issued to the April 2024 Purchasers divided by the exercise price of $3.25, subject to any adjustment to give effect to any stock dividend, stock split or recapitalization. The Company accounted for the April 2024 Warrants in accordance with ASC Topic 815, Derivatives and Hedging, and determined that at issuance, the April 2024 Warrants should be classified as a warrant liability. During the three-month period ended September 30, 2025, all of the outstanding April 2024 Warrants were exercised.

On November 21, 2025, the Company adopted a limited-duration shareholder rights plan (the "Rights Plan") pursuant to a Shareholder Rights Plan Agreement dated November 21, 2025 (the "Original Rights Plan Agreement"), between the Company and Computershare Investor Services Inc., as rights agent (the "Rights Agent"). One right (a "Right") was issued for each Common Share outstanding as of December 4, 2025, and a Right automatically attaches to each Common Share subsequently issued until the expiration of the Rights Plan. The Rights generally become exercisable only if a person or group acquires, or announces the current intention of commencing a take-over bid to acquire, beneficial ownership of 20% or more of the Company's outstanding Common Shares, other than through a permitted bid made in compliance with applicable Canadian take-over bid rules. If the Rights become exercisable, each holder of a Right, other than the acquiring person, would be entitled to purchase additional Common Shares at a discount to the then-current market price. The Rights Plan was not adopted in response to any specific take-over proposal.

On April 6, 2026, following approval by the Company's shareholders at the Company's annual general meeting, the Company and the Rights Agent entered into an Amended and Restated Shareholder Rights Plan Agreement (the "Amended Rights Plan Agreement"), which amended and restated the Original Rights Plan Agreement in its entirety. Under the Amended Rights Plan Agreement, the Rights Plan expires at 5:00 p.m. (Toronto time) on the date of the Company's annual general meeting of shareholders to be held in 2027, or earlier upon the redemption of the Rights or, provided that a triggering event has not occurred, at such earlier date or time as the Board of Directors may determine in its sole discretion.

Neither the adoption of the Original Rights Plan Agreement nor the subsequent entry into the Amended Rights Plan Agreement had an impact on the Company's consolidated financial statements for the year ended June 30, 2026.