Solana Co-A美股招股说明书（2026年5月29日版）

Up to $250,000,000 of ClassA Common Stock We have previously entered into a sales agreement with Clear Street LLC (“Clear Street”) and MaximGroup LLC (“Maxim,” and together with Clear Street, the “Sales Agents”) dated September15, 2025 (the“Prior Sales Agreement”), which was amended and restated on May 29, 2026 (the “Sales Agreement”),relating to shares of our ClassA common stock, par value $0.001 per share (the “common stock”), offeredby this prospectus supplement and the accompanying prospectus. In accordance with the terms of the SalesAgreement, pursuant to this prospectus supplement, we may offer and sell shares of our common stockhaving an aggregate offering price of up to $250,000,000 from time to time through the Sales Agents,reflecting an increase in the maximum aggregate offering price covered by the prior prospectus supplement(as defined below). As of the date of this prospectus supplement, we have issued and sold shares of our Our common stock is listed on The Nasdaq Capital Market (“Nasdaq”), under the symbol “HSDT.” OnMay 28, 2026, the last reported sale price of our common stock on Nasdaq was $2.04 per share. Sales of shares of our common stock, if any, made through the Sales Agents, or directly to the SalesAgents, as principals, as contemplated in this prospectus supplement and the accompanying prospectus, maybe made in negotiated transactions or transactions that are deemed to be “at the market offerings” as definedin Rule415(a)(4) promulgated under the Securities Act of 1933, as amended, or the Securities Act. TheSales Agents are not required to sell any specific amount of shares of common stock, but will act as oursales agent using commercially reasonable efforts consistent with its normal trading and sales practices andapplicable law and regulations, on mutually agreed terms between the Sales Agents and us. There is noarrangement for funds to be received in any escrow, trust or similar arrangement. The compensation to theSales Agents for sales of common stock sold pursuant to the Sales Agreement will be in an amount up to Under the terms of the Sales Agreement, we also may sell our common stock to the Sales Agents, asprincipals for their own accounts, at a price agreed upon at the time of sale. If we sell our common stock tothe Sales Agents, as principals, we will enter into a separate agreement with the Sales Agents, setting forththe terms of such transaction, and we will describe the agreement in a separate prospectus supplement or Investing in our common stock involves a high degree of risk. You should read this prospectus supplement,the accompanying prospectus and the documents incorporated by reference herein and therein before you makeyour investment decision. See “Risk Factors” beginning on pageS-3of this prospectus supplement and page4 ofthe accompanying prospectus, and under similar headings in the other documents incorporated by referenceherein, to read about risks that you should consider before making a decision to purchase shares of our common Neither the Securities and Exchange Commission nor any state securities commission has approved ordisapproved of these securities or determined if this prospectus supplement and the accompanying prospectus istruthful or complete. Any representation to the contrary is a criminal offense. Clear Street Maxim Group LLC The date of this prospectus supplement is May 29, 2026. ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement is part of a shelf registration statement on Form S-3 that we filed with theSecurities and Exchange Commission (the “SEC”). This document is in two parts. This first part is thisprospectus supplement, which describes the specific terms of the common stock we are offering and alsoadds to and updates information contained in the accompanying prospectus and the documents incorporatedby reference therein. The second part is the accompanying prospectus, which provides more generalinformation about securities we may offer from time to time, some of which does not apply to this offering.Generally, when we refer to this prospectus supplement, we are referring to both parts of this document You should rely only on the information contained in, or incorporated by reference into, this prospectussupplement, the accompanying prospectus or in any other prospectus supplement or free writing prospectusthat we may authorize for use in connection with this offering. We have not, and the Sales Agents have not,authorized any other person to provide you with different or additional information. If anyone provides youwith different, additional or inconsistent information, you should not rely on it. We are not, and the SalesAgents are not, making an offer to sell or soliciting an offer to buy our securities in any jurisdiction inwhich an offer or solicitation is not authorized or in which the person making that offer or solicitation is notqualified to do so or to anyone to whom it is unlawful to make an offer or solicitati