Tecogen director exercises options for 50,000 shares

TECOGEN INC. director John Hatsopoulos exercised stock options to acquire 50,000 shares of Common Stock at $0.88 per share under a Stock Option Agreement dated September 20, 2023.

Rhea-AI Filing Summary

TECOGEN INC. director John Hatsopoulos exercised stock options to acquire 50,000 shares of Common Stock at $0.88 per share under a Stock Option Agreement dated September 20, 2023. Following the exercise, he directly owns 1,038,951 shares of Tecogen Common Stock, indicating an exercise-and-hold transaction with no same-day share sale disclosed.

Insider Trade Summary

50,000 shares exercised/converted

Exercise 2 txns

Insider Hatsopoulos John

Role Director

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy)	50,000	$0.88	$44K
Exercise	Common Stock	50,000	$0.88	$44K

Holdings After Transaction: Stock Option (Right to Buy) — 0 contracts (Direct); Common Stock — 1,038,951 shares (Direct)

Footnotes (2)

1. F1. Shares acquired pursuant to exercise of Stock Option Agreement dated 9/20/2023
2. F2. Exercise of Stock Option Agreement dated 9/20/2023

FAQ

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

What insider transaction did Tecogen (TGEN) director John Hatsopoulos report?

John Hatsopoulos reported exercising stock options to acquire 50,000 Tecogen Common shares. The options carried an exercise price of $0.88 per share and arose from a Stock Option Agreement dated September 20, 2023, converting a derivative position into direct share ownership.

Did John Hatsopoulos buy Tecogen (TGEN) shares on the open market?

No, the filing shows a stock option exercise, not an open-market purchase. Hatsopoulos converted 50,000 options into Common Stock at the $0.88 exercise price under a 2023 option agreement, increasing his direct share holdings without reporting any market trade in this filing.

How many Tecogen (TGEN) shares does John Hatsopoulos own after this Form 4?

After the reported option exercise, John Hatsopoulos directly owns 1,038,951 Tecogen Common shares. This total reflects adding the 50,000 shares issued upon exercising the stock options described in the filing, with no same-day share disposition disclosed in the reported transactions.

What was the exercise price of the Tecogen (TGEN) stock options used by John Hatsopoulos?

The stock options were exercised at an exercise price of $0.88 per share. Exercising 50,000 options at this price converted a derivative security into the same number of Tecogen Common shares, as disclosed in the Form 4 transaction details and supporting footnotes.

Were all reported Tecogen (TGEN) derivative options exercised in this Form 4?

The filing shows a derivative transaction for 50,000 stock options and an empty remaining derivative position summary. This indicates the reported 50,000 options tied to the September 20, 2023 agreement were fully exercised into Common Stock in this transaction.

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

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Accepted by SEC EDGAR 03/23/2026 - 02:32 PM EDT 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).

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^*

Hatsopoulos John

(Last) (First) (Middle)

C/O TECOGEN INC.

76 TREBLE COVE ROAD

(Street)

NORTH BILLERICA MASSACHUSETTS 01862

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
TECOGEN INC. [ TGEN ]

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)
03/20/2026

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	03/20/2026		M		50,000(1)	A	$0.88	1,038,951	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
Stock Option (Right to Buy)	$0.88	03/20/2026		M			50,000(2)	09/20/2024	09/20/2033	Common Stock	50,000	$0.88	0	D

Explanation of Responses:

1. Shares acquired pursuant to exercise of Stock Option Agreement dated 9/20/2023

2. Exercise of Stock Option Agreement dated 9/20/2023

Remarks:

	/s/ John N. Hatsopoulos	03/23/2026
	** 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)