Portolan Capital Management Increases Stake in Tecogen Inc. to 5.19%

On June 10, 2026, Portolan Capital Management, LLC, and its manager George McCabe, filed a Schedule 13G with the SEC, reporting a significant increase in their stake in Tecogen Inc. (TGEN). As of the event date on June 3, 2026, the reporting persons beneficially own 1,552,232 shares of common stock, representing a 5.19% ownership interest in the company. This marks a substantial increase from their previously reported position of 443,555 shares. Portolan Capital Management, LLC, acting as a registered investment adviser for various clients, holds sole voting and dispositive power over the reported shares. The filing indicates that the securities were acquired in the ordinary course of business and not for the purpose of influencing or changing the control of the issuer. The reporting persons are based in Boston, Massachusetts, and filed this statement under Rule 13d-1(c).