On August 23, 2024, at a Special Meeting of Stockholders (the “Special Meeting”), the stockholders of ESS Tech, Inc. (the “Company”) authorized and approved proposed amendments to the Company’s certificate of incorporation to effect, at the discretion of the Company’s board of directors (the “Board”), a reverse stock split of all of the shares of the Company’s common stock that are issued and outstanding or held in treasury at a ratio of 1-for-8, 1-for-10, 1-for-12, 1-for-15, 1-for-20 or 1-for-25 and reduce the total number of authorized shares of common stock from 2,000,000,000 to 1,000,000,000 (the “Reverse Stock Split Proposal”). Additional information about the stockholder vote is provided under Item 5.07 below. On August 23, 2024, following the Special Meeting, the Board approved the reverse stock split at a ratio of 1-for-15 (the “Reverse Stock Split”).

On August 23, the Company filed a certificate of amendment to the Company’s Certificate of Incorporation (the “Charter Amendment”) with the Secretary of State of the State of Delaware to effect the Reverse Stock Split, effective as of 4:01 p.m., Eastern Time, on August 23, 2024 (the “Effective Time”). The Company’s common stock is expected to begin trading on a reverse-split-adjusted basis on the New York Stock Exchange (“NYSE”) as of the open of trading on August 26, 2024 under the existing ticker symbol “GHW”. The CUSIP number for the Company’s common stock will change to 26916J 205 following the Reverse Stock Split. The public warrants will continue to trade under the ticker symbol “GWH.W” and the CUSIP number for the Company’s publicly traded warrants will not change.

As of the Effective Time, every 15 shares of the Company’s common stock outstanding or held in treasury were combined into one share of common stock outstanding or held in treasury. The total number of authorized shares of common stock was reduced from 2,000,000,000 to 1,000,000,000. The par value of the Company’s common stock remained unchanged at $0.0001 per share. No scrip or fractional shares will be issued if, as a result of the Reverse Stock Split, a registered stockholder is otherwise entitled to a fractional share. Instead, any fractional shares of common stock that would otherwise be issuable as a result of the Reverse Stock Split will be paid out in cash, with reference to the closing price of the common stock as reported on NYSE on the trading day immediately preceding the Effective Time (as adjusted to give effect to the Reverse Stock Split), without interest.

As of the Effective Time, proportional adjustments to reflect the Reverse Stock Split were also made to the number of shares of common stock issuable upon the exercise of the Company’s stock options, the number of shares issuable pursuant to outstanding restricted stock units, the number of shares authorized and reserved for issuance pursuant to the Company’s equity compensation plans and the number of shares issuable upon exercise of the Company’s warrants to purchase common stock. The exercise prices of outstanding stock options, warrants, and equity awards were also proportionately adjusted, as applicable.

The Company’s transfer agent, Computershare Inc., is serving as the exchange agent for the Reverse Stock Split. Registered stockholders holding pre-reverse-split shares of the Company’s common stock electronically in book-entry form are not required to take any action to receive post-reverse-split shares or, if applicable, cash payment in lieu of any fractional share interest. Those stockholders who hold their shares in brokerage accounts or in “street name” will have their positions automatically adjusted to reflect the Reverse Stock Split, subject to each brokers’ particular processes, and are encouraged to contact the banks, brokers or nominees of such brokerage accounts regarding any questions.