X0609 4 2026-07-21 0 0001805077 Eos Energy Enterprises, Inc. EOSE 0001762220 Urban David false C/O EOS ENERGY ENTERPRISES, INC. TWO ALLEGHENY CENTER, NOVA TOWER 2 PITTSBURGH PA 15212 1 0 0 0 0 Common Stock 2026-07-21 4 M 0 12185 5.48 A 97767 D Subscription Rights (right to buy) 5.48 2026-07-21 4 M 0 12185 0 D 2026-07-21 Common Stock 12185 0 D Warrant (right to buy) 5.48 2026-07-21 4 M 0 5347 0 A Common Stock 5347 5347 D Represents the conversion of a subscription right issued by the Issuer as part of a rights offering that closed on July 21, 2026 (the "Rights Offering"). Each subscription right was exercisable for units that consisted of (i) 1 share of common stock and (ii) 0.4388 of a warrant exercisable to acquire a share of common stock at an exercise price of $5.48 per share. Warrants became exercisable immediately after the Rights Offering closed and expire 10 years later, unless exercised or redeemed earlier. If a warrant is not exercised or redeemed before it expires, it will have no value. /s/ Sumeet Puri as attorney-in-fact for David Urban 2026-08-06