ESS Tech Inc美股招股说明书(2025-07-22版)

Pursuant to this prospectus supplement, the prospectus supplement dated July 11, 2025 and the base prospectus datedNovember 17, 2022 (as supplemented from time to time, the “Prospectus”), we are offering 500,000 shares of our common stock to YA II PN, Ltd., a Cayman Islands exempt limited partnership (“Yorkville”), at a price of approximately $1.55 per share, pursuant toour previously announcedStandby Equity Purchase Agreement with Yorkville dated July 9, 2025 (the “SEPA”). These shares arebeing issued as part of the commitment by Yorkville to purchase from time to time shares of our common stock pursuant to the SEPA.The total purchase price of the shares is approximately $773,450. We used the proceeds from the issuance of the shares in this offeringto repay the remainder of the principal amount owed to Yorkville and certain directors and members of management of the Companypursuant to an outstanding bridge loan. We intend to use the additional net proceeds to continue normal business operations related toour strategic pivot focused on the Energy Base product and ongoing contracting activities. We expect to issue the shares to Yorkvilleon or about July 22, 2025. risk of loss), and without any view or intention to distribute such shares in violation of the Securities Act of 1933, as amended (the“Securities Act”), or any other applicable securities laws, the Securities and Exchange Commission (the “SEC”) may take the positionthat Yorkville may be deemed an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act and any profits on thesales of shares of our common stock by Yorkville and any discounts, commissions or concessions received by Yorkville are deemed tobe underwriting discounts and commissions under the Securities Act. For additional information on the methods of sale that may beused by Yorkville, see the section entitled “Plan of Distribution” on page S-12 of the prospectus supplement dated July 11, 2025 andpage 33 of the base prospectus dated November 17, 2022.Our shares of common stock are listed on the NYSE under the symbol “GWH.” On July 21, 2025, the closing sale price of our Neither the SEC nor any other regulatory body has approved or disapproved of these securities or passed upon theaccuracy or adequacy of the Prospectus. Any representation to the contrary is a criminal offense. Neither we nor Yorkville have authorized anyone to provide you with any information other than the informationcontained in or incorporated by reference in this prospectus supplement, or the prospectus supplement dated July 11, 2025 and base prospectus dated November 17, 2022 and in the documents incorporated by reference herein and therein. We andYorkville take no responsibility for, and can provide no assurance as to the reliability of, any other information that othersmay give you. We are not making an offer of these securities in any state or jurisdiction where the offer is not permitted. You should assume that the information contained in or incorporated by reference in this prospectus supplement, or the prospectussupplement dated July 11, 2025 and base prospectus dated November 17, 2022 is accurate only as of their respective dates. The OfferingSecurities offered500,000 shares of common stock of ESS Tech, Inc.Common stock WHERE YOU CAN FIND MORE INFORMATIONWe file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are availableto the public over the Internet at the SEC’s website at www.sec.gov. Copies of certain information filed by us with the SEC are also