Tecogen Inc.
TGEN- Exchange
- NYSE
- Industry
- Air-Cond & Warm Air Heatg Equip & Comm & Indl Refrig Equip
- SEC CIK
- 0001537435
No open-market purchases or sales by Tecogen Inc. insiders were filed in the last 90 days; 69 institutions reported holding it in 13F filings for Q2 2026, worth $49.5M in total; no superinvestor holds it.
Holders of 5% or more of TGEN
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Tecogen Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Portolan Capital Management, LLC | 13G | 5.19%1.55M shares | New | Jun 10, 20261 filing | Jun 10, 2026 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
2 Schedule 13D and 13G filings on Tecogen Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Jun 10, 20265:59 PM ET | Portolan Capital Management, LLCand 1 other | 13G | 5.19%1.55M shares | New | Jun 3, 2026 | SEC |
| Aug 14, 20255:25 PM ET | Natsis Tryfon | 13G/A | 1.80%460.3K shares | –Below 5% | Jun 30, 2025 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Tecogen Inc. shares.
No Form 144 notices for Tecogen Inc. are on file.