Comparable stake leader
Tryfon Natsis
SEC ownership of TECOGEN INC.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001537435.
Disclosed value leader
John N. Hatsopoulos
Comparable rows
50/50
Latest evidence
24 Apr 2026
- Public ticker
- TGEN on NYSE
- Parsed ownership sources
- 13D/G, 3/4/5, and 13F
- Largest SEC-reported holder
- Tryfon Natsis
- Latest 13D/G holder
- Tryfon Natsis
- Latest parsed ownership date
- 24 Apr 2026
- Issuer CIK
- 0001537435
- Issuer location
- North Billerica, MA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of TECOGEN INC. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
Tryfon Natsis
Disclosed value leader
John N. Hatsopoulos
Comparable rows
50/50
Latest evidence
24 Apr 2026
13D/G
3/4/5
13F
Lead comparable stake: 1.8%
13D/G row: Tryfon Natsis
Showing 1-8 of 50 holder rows.
Quick read
Tryfon Natsis leads the comparable SEC ownership view at 1.8%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens Tryfon Natsis's linked filing trail.
Comparable ownership
Top 5
Tryfon Natsis
1.8%
John N. Hatsopoulos
4.1%
Ahmed Ghoniem
0.05%
VANGUARD CAPITAL MANAGEMENT LLC
3%
BARD ASSOCIATES INC
2.7%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| Tryfon Natsis |
13D/G
Tryfon Natsis and Depoina Pantopoulou, as Joint Tenants with the Right of Survivorship
|
1.8%
|
$3,650,179
460,300 shares
|
$0 | 30 Jun 2025 |
| John N. Hatsopoulos |
3/4/5
Director
|
4.1%
|
$3,795,419
1,038,951 shares
mixed-class rows
|
— | 20 Mar 2026 |
| Ahmed Ghoniem |
3/4/5
Director
|
0.05%
|
$1,994,987
12,723 shares
mixed-class rows
|
+$10,000 | 24 Apr 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
3%
|
$1,971,108
769,964 shares
|
— | 31 Mar 2026 |
| BARD ASSOCIATES INC |
13F
Company
|
2.7%
|
$1,762,072
688,309 shares
|
— | 31 Mar 2026 |
| Clear Harbor Asset Management, LLC |
13F
Company
|
2.5%
|
$1,664,000
650,000 shares
|
— | 31 Mar 2026 |
| Portolan Capital Management, LLC |
13F
Company
|
1.7%
|
$1,135,501
443,555 shares
|
— | 31 Mar 2026 |
| HERALD INVESTMENT MANAGEMENT Ltd |
13F
Company
|
1.6%
|
$1,079,400
420,000 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$289,263.
Buys
$134,049
Insiders: 6
Sells
$423,312
Insiders: 2
Net
-$289,263
Shares: -9,977
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 60,723
Shares: 70,700
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 60,723 | 0 | $134,049 | $0 | +$134,049 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 70,700 | $0 | $423,312 | -$423,312 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-15 of 15 reporting-owner rows connected to TECOGEN INC.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
15
Largest Forms 3/4/5 holder
John N. Hatsopoulos
Net 12M change
-$139,763
Latest report
24 Apr 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| John N. Hatsopoulos | Director | $3,795,419 | Mixed | 20 Mar 2026 | ||
| John K. Whiting IV | General Counsel & Secretary | $3,594,842 | +$23,800 | +0.67% | Mixed | 23 Mar 2026 |
| Earl R. Lewis | Director | $3,308,863 | +$27,005 | +0.82% | Mixed | 27 Mar 2026 |
| Ann Marie Brown Pacheco | Trustee, 10%+ Owner | $2,886,674 | Mixed | 04 May 2022 | ||
| Abinand Rangesh | Chief Executive Officer, Director, Chief Financial Officer | $2,710,536 | +$6,894 | +0.25% | Mixed | 20 Mar 2026 |
| Susan B. Hirsch | Director | $2,242,501 | +$44,050 | +2% | Mixed | 13 Apr 2026 |
| Ahmed Ghoniem | Director | $1,994,987 | +$10,000 | +0.5% | Mixed | 24 Apr 2026 |
| Angelina Galiteva | Director | $1,878,750 | Mixed | 24 Jul 2025 | ||
| John M. Albertine | Director | $1,461,250 | Mixed | 24 Jul 2025 | ||
| Roger P. Deschenes | Cao | $1,387,831 | +$22,300 | +1.6% | Mixed | 20 Mar 2026 |
| Stephen Lafaille | VP of Business Development | $712,542 | Mixed | 24 Jul 2025 | ||
| Robert A. Panora | COO and President | $521,207 | -$273,812 | -34% | Mixed | 16 Jun 2025 |
| Fred Holubow | Director | $154,000 | Mixed | 13 Jun 2023 | ||
| Ralph Jenkins | Director | $132,000 | Mixed | 23 Jun 2022 | ||
| Benjamin M. Locke | CEO, Director | $4,616 | Mixed | 16 Mar 2022 |
Recent insider transactions for TECOGEN INC.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Ahmed Ghoniem | TGEN | Common Stock | Purchase | $10,000 | $0.7860 | 12,723 | 12,723 | 24 Apr 2026 | Direct | |
| Ahmed Ghoniem | TGEN | Stock Option (Right to Buy) | Options Exercise | -100% | -12,723 | 0 | 24 Apr 2026 | Direct | ||
| Susan F. Hirsch | TGEN | Common Stock | Purchase | 1.92% | $18,650 | $3.73 | 5,000 | 265,416 | 13 Apr 2026 | Direct |
| Susan F. Hirsch | TGEN | Common Stock | Purchase | 3.99% | $25,400 | $2.54 | 10,000 | 260,416 | 27 Mar 2026 | Direct |
| Earl R. Lewis | TGEN | Common Stock | Purchase | 0.5% | $12,596 | $2.52 | 5,000 | 1,011,006 | 27 Mar 2026 | Direct |
| Earl R. Lewis | TGEN | Common Stock | Purchase | 0.5% | $14,408 | $2.88 | 5,000 | 1,006,006 | 26 Mar 2026 | Direct |
| John K. Whiting IV | TGEN | Common Stock | Purchase | 79.3% | $23,800 | $2.38 | 10,000 | 22,612 | 23 Mar 2026 | Direct |
| Roger P. Deschenes | TGEN | Common Stock | Purchase | 23.3% | $22,300 | $2.23 | 10,000 | 52,962 | 20 Mar 2026 | Direct |
| Abinand Rangesh | TGEN | Common Stock | Purchase | 4.67% | $6,894 | $2.30 | 3,000 | 67,193 | 20 Mar 2026 | Direct |
| John N. Hatsopoulos | TGEN | Common Stock | Options Exercise | 5.06% | 50,000 | 1,038,951 | 20 Mar 2026 | Direct | ||
| John N. Hatsopoulos | TGEN | Stock Option (Right to Buy) | Options Exercise | -100% | -50,000 | 0 | 20 Mar 2026 | Direct | ||
| John M. Albertine | TGEN | Stock Option (Right to Buy) | Award | 16.7% | 25,000 | 175,000 | 24 Jul 2025 | Direct | ||
| Stephen Lafaille | TGEN | Common Stock | Award | 2994% | 11,976 | 12,376 | 24 Jul 2025 | Direct | ||
| Stephen Lafaille | TGEN | Stock Option (Right to Buy) | Award | 49.3% | 24,075 | 72,937 | 24 Jul 2025 | Direct | ||
| John K. Whiting IV | TGEN | Common Stock | Award | 1883% | 11,976 | 12,612 | 24 Jul 2025 | Direct | ||
| John K. Whiting IV | TGEN | Stock Option (Right to Buy) | Award | 6.02% | 24,075 | 424,075 | 24 Jul 2025 | Direct | ||
| Roger P. Deschenes | TGEN | Common Stock | Award | 71.9% | 17,964 | 42,962 | 24 Jul 2025 | Direct | ||
| Roger P. Deschenes | TGEN | Stock Option (Right to Buy) | Award | 8.62% | 12,063 | 152,063 | 24 Jul 2025 | Direct | ||
| Abinand Rangesh | TGEN | Common Stock | Award | 523.2% | 53,892 | 64,193 | 24 Jul 2025 | Direct | ||
| Abinand Rangesh | TGEN | Stock Option (Right to Buy) | Award | 13.4% | 36,123 | 306,123 | 24 Jul 2025 | Direct | ||
| Susan B. Hirsch | TGEN | Stock Option (Right to Buy) | Award | 20% | 25,000 | 150,000 | 24 Jul 2025 | Direct | ||
| Ahmed Ghoniem | TGEN | Stock Option (Right to Buy) | Award | 11.8% | 25,000 | 237,723 | 24 Jul 2025 | Direct | ||
| Earl R. Lewis | TGEN | Stock Option (Right to Buy) | Award | 37.7% | 25,000 | 91,250 | 24 Jul 2025 | Direct | ||
| Angelina Galiteva | TGEN | Stock Option (Right to Buy) | Award | 12.5% | 25,000 | 225,000 | 24 Jul 2025 | Direct | ||
| Robert A. Panora | TGEN | Common Stock | Sale | -1.42% | $6,174 | $6.86 | -900 | 62,523 | 24 Jun 2025 | Direct |
| Robert A. Panora | TGEN | Common Stock | Sale | -33.4% | $202,248 | $6.36 | -31,800 | 63,423 | 23 Jun 2025 | Direct |
| Stephen Lafaille | TGEN | Common Stock | Sale | -96.2% | -10,000 | 400 | 23 Jun 2025 | Direct | ||
| Stephen Lafaille | TGEN | Common Stock | Exercise of in-the-money or at-the-money derivative security | 2500% | 10,000 | 10,400 | 23 Jun 2025 | Direct | ||
| Stephen Lafaille | TGEN | Stock Options (Right to Buy) | Exercise of in-the-money or at-the-money derivative security | -36.4% | -10,000 | 17,500 | 23 Jun 2025 | Direct | ||
| Robert A. Panora | TGEN | Common Stock | Sale | -12% | $65,390 | $5.03 | -13,000 | 95,223 | 18 Jun 2025 | Direct |
| Robert A. Panora | TGEN | Common Stock | Options Exercise | 732.5% | 95,223 | 108,223 | 16 Jun 2025 | Direct | ||
| Robert A. Panora | TGEN | Stock Option (Right to Buy) | Options Exercise | -100% | -95,223 | 0 | 16 Jun 2025 | Direct | ||
| Robert A. Panora | TGEN | Common Stock | Exercise of in-the-money or at-the-money derivative security | 136% | 95,223 | 165,223 | 16 Jun 2025 | Direct | ||
| Stephen Lafaille | TGEN | Common Stock | Sale | -98.4% | $149,500 | $5.98 | -25,000 | 400 | 06 Jun 2025 | Direct |
| Stephen Lafaille | TGEN | Common Stock | Exercise of in-the-money or at-the-money derivative security | 6250% | 25,000 | 25,400 | 06 Jun 2025 | Direct | ||
| Stephen Lafaille | TGEN | Stock Options (Right to Buy) | Exercise of in-the-money or at-the-money derivative security | -47.6% | -25,000 | 27,500 | 06 Jun 2025 | Direct |
* marks a reported price that did not pass the local price check.