STOCK TITAN

Tax-driven Eos Energy (NASDAQ: EOSE) insider share sale detailed

Filing Impact
(Neutral)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Eos Energy Enterprises Chief Administration Officer Michelle Buczkowski reported a mix of equity award vesting and related share sales. On June 26, 2026, 22,938 restricted stock units converted into the same number of common shares at $0.00 per share under a company incentive plan.

On June 30, 2026, she sold 11,469 common shares in open-market transactions at a weighted-average price of $5.87 per share, effected automatically under a pre-arranged Rule 10b5-1 trading plan to cover estimated tax-withholding obligations tied to the vesting. After these transactions, she directly holds 59,242 common shares and 45,876 restricted stock units.

Positive

  • None.

Negative

  • None.
Insider Buczkowski Michelle
Role Chief Administration Officer
Sold 11,469 shs ($67K)
Type Security Shares Price Value
Sale Common Stock 11,469 $5.87 $67K
Exercise Restricted Stock Units 22,938 $0.00 --
Exercise Common Stock 22,938 $0.00 --
Holdings After Transaction: Common Stock — 59,242 shares (Direct, null); Restricted Stock Units — 45,876 shares (Direct, null)
Footnotes (1)
  1. Each restricted stock unit ("RSU") represents a contingent right to receive one share of common stock. The sales reported in this Form 4 were effected automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 11, 2025 to cover estimated tax withholding obligations in connection with the vesting of restricted stock units. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $5.68 to $6.15, 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. The reporting person received a grant of RSUs under the Issuer's 2020 Incentive Plan, which will vest in three equal installments on each of the first three anniversaries of the grant date, subject to continued service through each vesting date. Not applicable.
Common shares sold 11,469 shares Open-market sale on June 30, 2026
Average sale price $5.87 per share Weighted-average for June 30, 2026 sale
RSUs converted 22,938 units RSUs converted into common stock on June 26, 2026
Shares held after transactions 59,242 shares Direct common stock holdings following reported trades
RSUs remaining 45,876 units Restricted stock units outstanding after conversion
Sale price range $5.68–$6.15 per share Price range for June 30, 2026 transactions
Rule 10b5-1 trading plan regulatory
"The sales reported ... were effected automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person..."
A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.
restricted stock unit financial
"Each restricted stock unit ("RSU") represents a contingent right to receive one share of common stock."
A restricted stock unit is a promise from a company to give an employee shares of stock after certain conditions are met, like staying with the company for a set amount of time. It’s like earning a bonus that turns into company stock once you’ve proven your commitment, making it a way to motivate and reward employees.
2020 Incentive Plan financial
"The reporting person received a grant of RSUs under the Issuer's 2020 Incentive Plan..."
weighted average price financial
"The price reported in Column 4 is a weighted average price."
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
vesting financial
"The sales ... to cover estimated tax withholding obligations in connection with the vesting of restricted stock units."
Vesting is the process by which you earn full ownership of something, like company stock or a retirement benefit, over time. It’s like earning the right to keep a gift piece by piece the longer you stay with a company, making sure employees stay committed before they receive all the benefits.
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Learn about SEC filing dates
SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
X
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Buczkowski Michelle

(Last)(First)(Middle)
C/O EOS ENERGY ENTERPRISES, INC.
3920 PARK AVENUE

(Street)
EDISON NEW JERSEY 08820

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Eos Energy Enterprises, Inc. [ EOSE ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
Chief Administration Officer
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
06/26/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock06/26/2026M22,938A$0(1)70,711D
Common Stock06/30/2026S(2)11,469D$5.87(3)59,242D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Restricted Stock Units(4)(1)06/26/2026M22,938 (5) (5)Common Stock22,938$045,876D
Explanation of Responses:
1. Each restricted stock unit ("RSU") represents a contingent right to receive one share of common stock.
2. The sales reported in this Form 4 were effected automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 11, 2025 to cover estimated tax withholding obligations in connection with the vesting of restricted stock units.
3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $5.68 to $6.15, 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.
4. The reporting person received a grant of RSUs under the Issuer's 2020 Incentive Plan, which will vest in three equal installments on each of the first three anniversaries of the grant date, subject to continued service through each vesting date.
5. Not applicable.
Remarks:
/s/ Michael Silberman as attorney-in-fact for Michelle Buczkowski06/30/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did EOSE executive Michelle Buczkowski report?

Michelle Buczkowski reported RSU vesting and a related share sale. 22,938 restricted stock units converted into common shares, and 11,469 common shares were sold in open-market trades to address tax obligations tied to the vesting.

How many EOSE shares did the insider sell and at what price?

She sold 11,469 Eos Energy common shares at a weighted-average price of $5.87 per share. The filing notes individual trades occurred between $5.68 and $6.15, with full trade-by-trade details available upon request.

Were the EOSE insider share sales made under a Rule 10b5-1 plan?

Yes. The filing states the sales were executed automatically under a Rule 10b5-1 trading plan adopted on December 11, 2025. The plan’s purpose was to cover estimated tax withholding obligations from restricted stock unit vesting.

How many EOSE shares and RSUs does the insider hold after these transactions?

Following the reported transactions, Michelle Buczkowski directly holds 59,242 Eos Energy common shares. She also holds 45,876 restricted stock units, which represent rights to receive additional shares as they vest over time.

What triggered the RSU conversion reported for EOSE’s Michelle Buczkowski?

The conversion came from a restricted stock unit grant under Eos Energy’s 2020 Incentive Plan. Those RSUs vest in three equal annual installments on each of the first three anniversaries of the grant date, subject to continued service.

Why were EOSE shares sold in connection with the RSU vesting?

The filing explains the sales were intended to cover estimated tax withholding obligations from RSU vesting. Using an automatic Rule 10b5-1 plan allows taxes to be satisfied without requiring separate discretionary sales at vesting.