Eos Energy Enterprises, Inc. (EOSE) Lock-Up & Share Unlock Dates

Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common stock, par value $0.0001 per share EOSE The Nasdaq Stock Market LLC Warrant, each whole warrant exercisable to purchase one share of Common Stock at an exercise price of $5.481 EOSEW The Nasdaq Stock Market LLC Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports); and (2) has been subject to such filing requirements for the past 90 da nergy storage systems operating in the field. Governance of Eos’s equity interests in FPUSA will be conducted through an independent investment committee, and transactions between the Company and FPUSA are expected to be conducted on arm’s-length commercial terms. FPUSA is targeting the development of a multi-gigawatt-hour pipeline of long-duration energy storage projects across data center, utility and industrial end markets, which is expected to further support the growth and visibility of the Company’s revenue profile over time. In connection with these arrangements, Cerberus has agreed to extend the lock-up period on its existing Eos holdings through December 21, 2026. Rights Offering In May 2026, in connection with the planned formation of FPUSA, the Company announced a rights offering (the “Rights Offering”) targeting approximately $150.0 million. In the Rights Offering, shareholders of Eos common stock and holders of its warrants to purchase common stock issued on April 14, 2023, May 17, 2023, December 19, 2023, and November 21, 2025 as of the record date of 5:00pm New York time on July 1, 2026 (collectively, “Eligible Holders”), would receive rights to acquire a certain number of units, comprised of the Company’s common stock and warrants (the “Units”) in a rights offering to fund the Company’s previously announced capital contribution in the FPUSA joint venture. On June 30, 2026, the Company announced updated terms for the rights offering such that each right was expected to entitle an Eligible Holder the right to purchase approximately 0.071193 of a Unit at a subscription price equal to $5.481 per whole Unit, an approximate 10% discount to the closing price of the Company’s common stock on June 29, 2026. Each Unit would consist of one share of Eos common stock and 0.4388 of a warrant, with each whole warrant entitling the holder to purchase one share of Eos common stock at an exercise price of $5.481 per share, subject to adjustment. The warrants are expected to expire on the 10 year anniversary of the closing of the rights offering. The Company elected to conduct the rights offering to ensure that all stockholders of record as of July 1, 2026 had the