Barnwell Industries Inc 美股招股说明书（2026年2月25日版）

PROSPECTUS SUPPLEMENT (To Prospectus dated January30, 2026) BARNWELL INDUSTRIES, INC. Up to $3,200,000 of Common Stock We have entered into a Sales Agreement (the “Sales Agreement”), dated February25, 2026, with RothCapital Partners, LLC (the “Sales Agent”), relating to the shares of our common stock, par value $0.50 per share(“Common Stock”), offered by this prospectus supplement. In accordance with the terms of the Sales Agreement,we may offer and sell shares of our Common Stock having an aggregate offering price of up to $50,000,000 fromtime to time through or to the Sales Agent, as agent or principal. However, due to the offering limitationsapplicable to us under General Instruction I.B.6. of Form S-3 and our public float calculated in accordancetherewith as of the date of this prospectus supplement, and in accordance with the terms of the sales agreement, Sales of Common Stock, if any, under this prospectus supplement and the accompanying prospectus may bemade in transactions that are deemed to be “at-the-market offerings” as defined in Rule415 under the SecuritiesAct of 1933, as amended (the “Securities Act”). The Sales Agent is not required to sell any specific number ordollar amount of shares, but will act as sales agent on a commercially reasonable efforts basis consistent with its We will pay the Sales Agent a commission of up to 2.5% of the gross sales price per share of Common Stockissued by us and sold through them as our Sales Agent under the Sales Agreement. In connection with the sale ofCommon Stock on our behalf, the Sales Agent will be deemed to be an “underwriter” within the meaning of theSecurities Act and the compensation to the Sales Agent will be deemed to be underwriting commissions or Investing in our common stock involves risks. See “Risk Factors” on page S-5of this prospectussupplement and on page2of the accompanying prospectus concerning factors you should consider before Our Common Stock is listed on the NYSE American LLC (“NYSE American”) under the symbol “BRN.”On February20, 2026 the last reported sale price of our Common Stock on NYSE American was $1.01 per share. The aggregate market value of our outstanding Common Stock held by non-affiliates was approximately$9,743,507, which was calculated based on 12,566,314 shares of outstanding common stock as of February20,2026 held by non-affiliates multiplied by a price per share of $1.17, the closing price of our Common Stock onJanuary27, 2026. Pursuant to General Instruction I.B.6 of FormS-3, in no event will we sell shares of ourCommon Stock pursuant to this prospectus supplement with a value of more than one-third of the aggregatemarket value of our Common Stock held by non-affiliates, or $3,247,836, in any 12 month period, so long as the Neither the Securities and Exchange Commission nor any state securities commission has approved ordisapproved of these securities or passed upon the accuracy or adequacy of this prospectus supplement. Roth Capital PartnersThe date of this prospectus supplement is February 25, 2026. TABLE OF CONTENTS You should rely only on the information we have provided or incorporated by reference in thisprospectus supplement and the accompanying prospectus. We have not, and the Sales Agent has not,authorized anyone to provide you with information different from that contained or incorporated by This prospectus supplement and any later prospectus supplement is an offer to sell only the securitiesoffered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. You should assume that the information contained in this prospectus supplement and in any otherprospectus supplement is accurate only as of their respective dates and that any information we haveincorporated by reference is accurate only as of the date of the document incorporated by reference, TABLE OF CONTENTS ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement and the accompanying prospectus relate to the sale of shares of our Common Stockregistered for sale under our Registration Statement on FormS-3 (File No. 333-292684) (the “RegistrationStatement”), which the Securities and Exchange Commission (the “Commission” or the “SEC”) declared effectiveon January 30, 2026. This document is in two parts. The first part is this prospectus supplement, which describes thespecific terms of this Common Stock offering and also adds to and updates information contained in theaccompanying prospectus and the documents incorporated by reference herein and therein. The second part, theaccompanying prospectus, provides more general information. Generally, when we refer to this prospectus, we arereferring to both parts of this document combined. To the extent there is a conflict between the information We further note that the representations, warranties and covenants made by us in any agreement that is filed asan exhibit to any document that is incorporated by reference herein were made solely for the benefit of