Plug Power director sells 50,000 shares under plan

PLUG POWER INC director Maureen O. Helmer reported an open-market sale of 50,000 shares of common stock at a weighted average price of $3.2324 per share.

Rhea-AI Filing Summary

PLUG POWER INC director Maureen O. Helmer reported an open-market sale of 50,000 shares of common stock at a weighted average price of $3.2324 per share. After this transaction, she directly holds 321,565 shares. The sale was executed under a pre-arranged Rule 10b5-1 trading plan adopted on March 9, 2026, indicating it was scheduled in advance rather than timed opportunistically.

Insights

Equity ownership and insider trading analyst

Director sold 50,000 PLUG shares under a pre-set 10b5-1 plan.

Director Maureen O. Helmer executed an open-market sale of 50,000 shares of PLUG POWER INC common stock at a weighted average of $3.2324 per share. This is a direct sale, not via an entity, and uses standard open-market mechanics.

The filing shows she continues to own 321,565 shares after the transaction, so she retains a substantial position. A footnote states the trades were made pursuant to a Rule 10b5-1 trading plan adopted on March 9, 2026, meaning the sales were pre-scheduled, which typically reduces the informational value of the exact timing.

Because this is a single, pre-planned director sale without other financial disclosures, it is best viewed as routine portfolio management rather than a clear signal about the company’s fundamentals or outlook.

Insider Trade Summary 10b5-1

Net Seller: 50,000 shares

Net Sell 1 txn

Insider HELMER MAUREEN O

Role Director

Sold 50,000 shs ($162K)

Type	Security	Shares	Price	Value
Sale	Common Stock	50,000	$3.2324	$162K

Holdings After Transaction: Common Stock — 321,565 shares (Direct)

Footnotes (2)

1. F1. These sales were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted on March 9, 2026.
2. F2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.17 to $3.33, inclusive. The Reporting Person undertakes to provide to 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.

Key Figures

Shares sold: 50,000 shares Weighted average sale price: $3.2324 per share Post-transaction holdings: 321,565 shares +2 more

5 metrics

Shares sold 50,000 shares Open-market sale on June 8, 2026

Weighted average sale price $3.2324 per share Common stock sale

Post-transaction holdings 321,565 shares Shares directly owned after sale

Sale price range $3.17–$3.33 per share Range of individual trade prices

Trading plan adoption date March 9, 2026 Rule 10b5-1 trading plan

Key Terms

Rule 10b5-1 trading plan, weighted average price, open-market sale, Form 4

4 terms

Rule 10b5-1 trading plan regulatory

"These sales were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted on March 9, 2026."

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.

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.

open-market sale financial

"transaction_action: open-market sale"

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Form 4 regulatory

"INSIDER FILING DATA (Form 4):"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did PLUG director Maureen Helmer report?

Maureen O. Helmer reported selling 50,000 shares of PLUG common stock in an open-market transaction. The weighted average sale price was $3.2324 per share, reflecting multiple trades within a disclosed price range between $3.17 and $3.33.

How many PLUG shares does Maureen Helmer hold after this Form 4 sale?

After the reported sale, Maureen O. Helmer directly holds 321,565 PLUG shares. This remaining stake shows she still maintains a sizeable ownership position in Plug Power Inc., even after disposing of 50,000 shares in the disclosed open-market transaction.

Was the PLUG insider sale by Maureen Helmer under a Rule 10b5-1 plan?

Yes. The filing notes the sales were effected under a Rule 10b5-1 trading plan adopted on March 9, 2026. Such plans pre-schedule trades, indicating the timing was set in advance rather than chosen reactively to short-term market events.

What price range did the PLUG shares sell for in Maureen Helmer’s transaction?

The Form 4 states that the 50,000 PLUG shares were sold in multiple trades at prices between $3.17 and $3.33 per share. The reported transaction price of $3.2324 per share is a weighted average across those individual executions.

Does Maureen Helmer’s PLUG Form 4 indicate a buy or sell transaction?

The Form 4 reports an open-market sale of PLUG common stock by Maureen O. Helmer. The SEC transaction code is “S,” which denotes a sale in the open market or a private transaction, rather than a purchase or option exercise.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 06/10/2026 - 04:05 PM Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED 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^*

HELMER MAUREEN O

(Last) (First) (Middle)

C/O PLUG POWER INC.

125 VISTA BOULEVARD

(Street)

SLINGERLANDS NEW YORK 12159

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
PLUG POWER INC [ PLUG ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/08/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form 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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	06/08/2026		S(1)		50,000	D	$3.2324(2)	321,565	D

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. These sales were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted on March 9, 2026.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.17 to $3.33, inclusive. The Reporting Person undertakes to provide to 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.

	/s/ Gerard L. Conway Jr., Attorney-in-Fact	06/10/2026
	** Signature of Reporting Person	Date
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)