SCHEDULE 13G/A

Tecogen Inc

Common Stock, $0.001 par value · CUSIP: 87876P201

Event date: 2025-06-30

Filing-level shares

460,300

Percent of class

1.8%

• Tryfon Natsis and Depoina Pantopoulou, as Joint Tenants with the Right of Survivorship

  Shares: 460,300 · Class: 1.8%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.