NioCorp Developments Ltd美股招股说明书(2026-01-20版)

4,250,000 Common Shares This prospectus supplement relates to the offer and sale from time to time of up to 4,250,000 of our common shares, without parvalue (“Common Shares”), consisting of Advance Shares (as defined below), by YA II PN, Ltd., a Cayman Islands exempt limitedpartnership (“YA” or the “Selling Shareholder”). YA is a fund managed by Yorkville Advisors Global, LP. The 4,250,000 CommonShares being offered pursuant to this prospectus supplement are in addition to the 10,588,617 Common Shares, consisting of the81,213 Commitment Shares (as defined below) and 10,507,404 Advance Shares (together with the Commitment Shares, the “PriorShares”), that were registered for resale by YA pursuant to the Company’s registration statement on Form S-3, originally filed onMarch 15, 2023, as amended and supplemented, including pursuant to Amendment No. 1 to Post-Effective Amendment No. 1 to FormS-3 on Form S-1, dated October 13, 2023 and declared effective on October 30, 2023, which converted such registration statement toForm S-1 (Registration No. 333-270542) (the “Prior Registration Statement”). The Common Shares being offered by the Selling Shareholder have been and may be issued pursuant to the Standby EquityPurchase Agreement, dated January 26, 2023, that we entered into with YA (the “Purchase Agreement”). We are not selling anysecurities under this prospectus supplement and will not receive any of the proceeds from the sale of Common Shares by the SellingShareholder. However, we may receive up to $65.0 million in aggregate gross proceeds (the “Commitment Amount”) from sales ofCommon Shares to YA that we may make under the Purchase Agreement, from time to time during the Commitment Period (asdefined below) (the “Advance Shares”), subject to certain limitations and the satisfaction of certain conditions. As of January 16, 2026,approximately $25.3 million of the Commitment Amount remains available for sales of Advance Shares under the PurchaseAgreement. The Advance Shares that may be offered pursuant to this prospectus supplement would be purchased by YA pursuant tothe Purchase Agreement at a purchase price equal to 97% of the daily volume-weighted average price of our Common Shares on thePrincipal U.S. Market (as defined below) as reported by Bloomberg Financial Markets (or, if not available, a similar service providerof national recognized standing) (“VWAP”) during the applicable pricing period, which is a period during a single trading day or aperiod of three consecutive trading days, at the Company’s option and subject to certain restrictions, in each case, defined based onwhen an Advance Notice (as defined below) is submitted, subject to certain limitations. See the section titled “The YA Transaction” for a description of the transaction contemplated by the Purchase Agreement and thesection titled “Selling Shareholder” for additional information regarding YA. The Selling Shareholder may sell the Common Shares included in this prospectus supplement in a number of differentways and at varying prices. We provide more information about how the Selling Shareholder may sell the Common Shares inthe section entitled “Plan of Distribution” beginning on page S-38 of this prospectus supplement. The Selling Shareholder is an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act of 1933 (the “SecuritiesAct”). The Selling Shareholder will pay all brokerage fees, commissions and similar expenses in connection with the offer and sale of theCommon Shares by the Selling Shareholder pursuant to this prospectus supplement. We will pay the expenses (except brokerage fees, commissions and similar expenses) incurred in registering under the Securities Act the offerand sale of the Common Shares included in this prospectus supplement by the Selling Shareholder. See “Plan of Distribution.” As of January 16, 2026, the Common Shares covered by this prospectus supplement would represent approximately 3.3% of thetotal number of outstanding Common Shares (assuming all of the Common Shares covered by this prospectus supplement were issuedand outstanding and not including Common Shares issuable upon exercise of outstanding stock options, or reserved for futureissuance, under the NioCorp Developments Ltd. Long-Term Incentive Plan (the “LTIP”) or Common Shares issuable upon conversion,exercise or exchange of other outstanding securities, as described herein). The Selling Shareholder will be able to sell all of theCommon Shares covered by this prospectus supplement for so long as the registration statement of which this prospectus supplementis a part is available for use and such Common Shares have been issued and sold to the Selling Shareholder in accordance with thePurchase Agreement. Accordingly, the sale of the Common Shares covered by this prospectus supplement, or the perception that suchsales may occur, could result in a significant decline in the public trading price of our Common Shares. Moreover, the sal