LAFAILLE STEPHEN (VP of Business Development) made both purchases and sales at TECOGEN INC.

Purchased 400.00 shares and sold 99.3% of their position (60K shares) — review individual transaction dates and prices for directional context.

P · 1S · 4

LAFAILLE STEPHEN

Filed: 6/24/2025ACC: 0001537435-25-000064

InsiderLAFAILLE STEPHENCIK 2074096

→

IssuerTECOGEN INC.CIK 1537435

Officer· VP of Business Development

Since Apr 2024

-59.60K

Net shares

Net seller

$345.8K

Total sold

Open market trades

1B · 4S

Total transactions

60.40K acquired · 120K disposed

Non-Derivative Transactions9

Common Stock

Direct

P · Purchase

+400.00

Price / share

$2.50

Trade value

$1K

% of position

New position

3/3/2025

0.00→400.00

Common Stock

Direct

X · X

+10K

Price / share

$0.71

Trade value

$7.10K

% of position

2500.0%

6/3/2025

400.00→10.40K

Common Stock

Direct

S · Sale

−10K

Price / share

$4.88

Trade value

$48.80K

% of position

96.2%

6/3/2025

10.40K→400.00

Common Stock

Direct

X · X

+15K

Price / share

$0.71

Trade value

$10.65K

% of position

3750.0%

6/4/2025

400.00→15.40K

Common Stock

Direct

S · Sale

−15K

Price / share

$5.00

Trade value

$75K

% of position

97.4%

6/4/2025

15.40K→400.00

Common Stock

Direct

X · X

+25K

Price / share

$1.10

Trade value

$27.50K

% of position

6250.0%

6/6/2025

400.00→25.40K

Common Stock

Direct

S · Sale

−25K

Price / share

$5.98

Trade value

$149.50K

% of position

98.4%

6/6/2025

25.40K→400.00

Common Stock

Direct

X · X

+10K

Price / share

$1.10

Trade value

$11K

% of position

2500.0%

6/23/2025

400.00→10.40K

Common Stock

Direct

S · Sale

−10K

Price / share

$7.25

Trade value

$72.50K

% of position

96.2%

6/23/2025

10.40K→400.00

Total

Net shares

+400.00

Net value

-$288.55K

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Common Stock Direct	3/3/2025	P · Purchase	+400.00	$2.50	$1K	New position	0.00	400.00
Common Stock Direct	6/3/2025	X · X	+10K	$0.71	$7.10K	2500.0%	400.00	10.40K
Common Stock Direct	6/3/2025	S · Sale	−10K	$4.88	$48.80K	96.2%	10.40K	400.00
Common Stock Direct	6/4/2025	X · X	+15K	$0.71	$10.65K	3750.0%	400.00	15.40K
Common Stock Direct	6/4/2025	S · Sale	−15K	$5.00	$75K	97.4%	15.40K	400.00
Common Stock Direct	6/6/2025	X · X	+25K	$1.10	$27.50K	6250.0%	400.00	25.40K
Common Stock Direct	6/6/2025	S · Sale	−25K	$5.98	$149.50K	98.4%	25.40K	400.00
Common Stock Direct	6/23/2025	X · X	+10K	$1.10	$11K	2500.0%	400.00	10.40K
Common Stock Direct	6/23/2025	S · Sale	−10K	$7.25	$72.50K	96.2%	10.40K	400.00
Total			+400.00		-$288.55K

Derivative Transactions4

Stock Options (Right to Buy)

Direct

X · X

Converts to

Common Stock

50K shares

−10K

Strike price

0.71

Held after

40K

Exercisable

—

6/3/2025

Stock Options (Right to Buy)

Direct

X · X

Converts to

Common Stock

40K shares

−15K

Strike price

0.71

Held after

25K

Exercisable

—

6/4/2025

Stock Options (Right to Buy)

Direct

X · X

Converts to

Common Stock

52.50K shares

−25K

Strike price

1.10

Held after

27.50K

Exercisable

—

6/6/2025

Stock Options (Right to Buy)

Direct

X · X

Converts to

Common Stock

25K shares

−10K

Strike price

1.10

Held after

17.50K

Exercisable

—

6/23/2025

Security	Converts To	Date	Type	Shares	Strike Price	Exercisable	Held After
Stock Options (Right to Buy) Direct	Common Stock50K shares	6/3/2025	X · X	−10K	0.71	—	40K
Stock Options (Right to Buy) Direct	Common Stock40K shares	6/4/2025	X · X	−15K	0.71	—	25K
Stock Options (Right to Buy) Direct	Common Stock52.50K shares	6/6/2025	X · X	−25K	1.10	—	27.50K
Stock Options (Right to Buy) Direct	Common Stock25K shares	6/23/2025	X · X	−10K	1.10	—	17.50K