Tecogen Stock Triples in Value as VP of Business Development Exits Position

Rhea-AI Filing Summary

Stephen Lafaille, VP of Business Development at Tecogen, reported significant insider trading activity through multiple transactions between March and June 2025. The transactions reveal a pattern of option exercises and subsequent stock sales at progressively higher prices.

Key transaction highlights:

• Initial purchase of 400 shares at $2.50 on March 3, 2025
• Exercised and sold multiple tranches of options: - 10,000 shares ($0.71 exercise, sold at ~$4.88) - 15,000 shares ($0.71 exercise, sold at $5.00) - 25,000 shares ($1.10 exercise, sold at ~$5.98) - 10,000 shares ($1.10 exercise, sold at $7.25)

The insider maintains ownership of 400 shares post-transactions. Notable option holdings include remaining rights to purchase 40,000 shares at $0.71 (expires 2030) and 45,000 shares at $1.10 (expires 2032), subject to vesting conditions tied to EBITDA performance metrics.

Positive

• VP of Business Development Stephen Lafaille realized significant gains through option exercises and stock sales, with sale prices ranging from $4.75 to $7.25 per share compared to exercise prices of $0.71-$1.10
• The stock price showed strong upward momentum, rising from $4.88 to $7.25 per share over the course of transactions from June 3-23, 2025
• The existence of performance-based vesting conditions tied to EBITDA margins (2-3% of revenue) suggests management incentives are aligned with profitability goals

Negative

• Significant insider selling activity with the executive disposing of all acquired shares (60,000 total shares) rather than maintaining ownership
• The VP of Business Development reduced his direct holdings to just 400 shares after all transactions, potentially signaling limited confidence in further upside
• Exercise and immediate sale of performance-based options could indicate the executive believes the stock is fully valued at current levels

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^*

Lafaille Stephen

(Last) (First) (Middle)

76 TREBLE COVE ROAD

(Street)

NORTH BILLERICA MA 01862

(City) (State) (Zip)

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

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	VP of Business Development

3. Date of Earliest Transaction (Month/Day/Year)
03/03/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

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

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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	03/03/2025		P		400	A	$2.5	400	D
Common Stock	06/03/2025		X		10,000	A	$0.71(1)	10,400	D
Common Stock	06/03/2025		S		10,000	D	$4.88(2)	400	D
Common Stock	06/04/2025		X		15,000	A	$0.71(1)	15,400	D
Common Stock	06/04/2025		S		15,000	D	$5(3)	400	D
Common Stock	06/06/2025		X		25,000	A	$1.1(4)	25,400	D
Common Stock	06/06/2025		S		25,000	D	$5.98(5)	400	D
Common Stock	06/23/2025		X		10,000	A	$1.1(4)	10,400	D
Common Stock	06/23/2025		S		10,000	D	$7.25	400	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 Options (Right to Buy)	$0.71	06/03/2025		X			10,000	(6)	07/09/2030	Common Stock	50,000	$0.71	40,000	D
Stock Options (Right to Buy)	$0.71	06/04/2025		X			15,000	(6)	07/09/2030	Common Stock	40,000	$0.71	25,000	D
Stock Options (Right to Buy)	$1.1	06/06/2025		X			25,000	01/21/2023(7)	01/21/2032	Common Stock	52,500	$1.1	27,500	D
Stock Options (Right to Buy)	$1.1	06/23/2025		X			10,000	01/21/2023(7)	01/21/2032	Common Stock	25,000	$1.1	17,500	D

Explanation of Responses:

1. Shares acquired pursuant to exercise of Stock Option Agreement dated 7/9/2020

2. Multiple share sales between $4.75 and $5.25 per share

3. 10,000 shares sold for $4.90 per share, and 5,000 shares sold for $5.10 per share

4. Shares acquired pursuant to stock option agreement dated 1/21/2022

5. Multiple share sales between $5.85 and $6.10

6. Vests 50% upon achievement of Adjusted EBITDA goal of 2% of revenue in two consecutive quarters, and 50% upon achievement of Adjusted EBITDA goal of 3% of revenue in four consecutive quarters

7. Vests 50% per year

Remarks:

	/s/ Stephen Lafaille	06/24/2025
	** 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.
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FAQ

What insider trading activity occurred at TGEN on June 23, 2025?

On June 23, 2025, Stephen Lafaille, VP of Business Development at TGEN, exercised 10,000 stock options at $1.10 per share and subsequently sold those 10,000 shares at $7.25 per share.

How many TGEN shares did Stephen Lafaille sell in June 2025?

Stephen Lafaille sold a total of 60,000 TGEN shares in June 2025 through multiple transactions: 10,000 shares on June 3 at around $4.88, 15,000 shares on June 4 at $5.00, 25,000 shares on June 6 at around $5.98, and 10,000 shares on June 23 at $7.25.

What is the exercise price of TGEN stock options held by Stephen Lafaille?

Stephen Lafaille holds two sets of TGEN stock options: ones granted on July 9, 2020 with an exercise price of $0.71, and others granted on January 21, 2022 with an exercise price of $1.10 per share.

How many TGEN shares does Stephen Lafaille own after all reported transactions?

Following all reported transactions, Stephen Lafaille directly owns 400 shares of TGEN common stock. He also retains beneficial ownership of unexercised stock options for 17,500 shares at $1.10 and 25,000 shares at $0.71.

What are the vesting conditions for TGEN's stock options granted to Stephen Lafaille?

TGEN's stock options have two different vesting schedules: The July 2020 options vest 50% upon achieving Adjusted EBITDA of 2% of revenue in two consecutive quarters and 50% upon achieving 3% of revenue in four consecutive quarters. The January 2022 options vest 50% per year.