Russell Monoki Stidolph - 05 Dec 2025 Form 4 Insider Report for Eos Energy Enterprises, Inc. (EOSE)

Role
Director
Signature
/s/ Michael Silberman as attorney-in-fact for Russell Stidolph
Issuer symbol
EOSE
Transactions as of
05 Dec 2025
Net transactions value
-$11,471,730
Form type
4
Filing time
08 Dec 2025, 21:13:07 UTC
Previous filing
21 May 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Stidolph Russell Monoki Director C/O ALTENERGY LLC, 137 ROWAYTON AVENUE, ROWAYTON /s/ Michael Silberman as attorney-in-fact for Russell Stidolph 08 Dec 2025 0001833275

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction EOSE Common Stock Sale $7,495,000 -500,000 -19% $14.99 2,153,272 05 Dec 2025 See footnote F1
transaction EOSE Common Stock Sale $460,785 -29,999 -1.4% $15.36 2,123,273 08 Dec 2025 See footnote F1, F2
transaction EOSE Common Stock Other $0 -75,000 -3.5% $0.000000 2,048,273 05 Dec 2025 See footnote F1, F3
transaction EOSE Common Stock Other $0 +75,000 +21% $0.000000 439,355 05 Dec 2025 Direct F3
transaction EOSE Common Stock Gift $0 -60,000 -14% $0.000000 379,355 05 Dec 2025 Direct F4
transaction EOSE Common Stock Gift $0 -15,000 -4% $0.000000 364,355 05 Dec 2025 Direct F5
transaction EOSE Common Stock Options Exercise $444,271 +30,788 +8.5% $14.43 395,143 08 Dec 2025 Direct
transaction EOSE Common Stock Tax liability $444,296 -30,020 -7.6% $14.80 365,123 08 Dec 2025 Direct
transaction EOSE Common Stock Sale $11,366 -768 -0.21% $14.80 364,355 08 Dec 2025 Direct
transaction EOSE Common Stock Options Exercise $171,121 +145,018 +40% $1.18 509,373 08 Dec 2025 Direct
transaction EOSE Common Stock Options Exercise $279,869 +120,633 +24% $2.32 630,006 08 Dec 2025 Direct
transaction EOSE Common Stock Tax liability $279,828 -18,793 -3% $14.89 611,213 08 Dec 2025 Direct F6
transaction EOSE Common Stock Tax liability $171,101 -11,491 -1.9% $14.89 599,722 08 Dec 2025 Direct F6
transaction EOSE Common Stock Sale $3,504,615 -235,367 -39% $14.89 364,355 08 Dec 2025 Direct F6

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction EOSE Stock Option (Right to Buy) Options Exercise $0 -30,788 -100% $0.000000 0 08 Dec 2025 Common Stock 30,788 $14.43 Direct F7
transaction EOSE Stock Option (Right to Buy) Options Exercise $0 -145,018 -100% $0.000000 0 08 Dec 2025 Common Stock 145,018 $1.18 Direct F8
transaction EOSE Stock Option (Right to Buy) Options Exercise $0 -120,633 -100% $0.000000 0 08 Dec 2025 Common Stock 120,633 $2.32 Direct F9
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 The shares reported in this Form 4 are shares of common stock in which Mr. Stidolph has a pecuniary interest in that are held directly by AltEnergy, LLC or AltEnergy Transmission, LLC. Mr. Stidolph is the managing director of AltEnergy, LLC and the managing member of AltEnergy Transmission, LLC and has voting and dispositive power with respect to the securities owned by AltEnergy, LLC and AltEnergy Transmission, LLC. Each of the Filing Persons disclaims beneficial ownership of the outstanding shares of common stock of the issuer reported herein except to the extent of its pecuniary interest therein.
F2 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.28 to $15.45, inclusive. The reporting person undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above.
F3 Represents the receipt, for no consideration, of an aggregate of 75,000 shares of Common Stock of the Issuer by AltEnergy pursuant to pro rata distribution by AltEnergy.
F4 Represents a charitable donation by the reporting person.
F5 Reflects the donation of common stock to a charitable donor advised fund.
F6 The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions pursuant to a Cashless exercise / same-day sale at prices ranging from $14.68 to $15.16, inclusive. The reporting person undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above.
F7 On December 8, 2020 the reporting person was granted stock options to purchase 30,788 shares of common stock which vested on June 15, 2021.
F8 On May 19, 2022 the reporting person was granted stock options to purchase 145,018 shares of common stock which vested on May 19, 2023.
F9 On May 18, 2023 the reporting person was granted stock options to purchase 120,633 shares of common stock which vested on April 30, 2024.