Annual report [Section 13 and 15(d), not S-K Item 405]

Stockholders??? Equity (Tables)

v3.26.1
Stockholders’ Equity (Tables) - Tecogen
12 Months Ended
Dec. 31, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Schedule of Stock Option Activity
Stock option activity for the year ended December 31, 2025 was as follows:
Common Stock Options Number of
Options
Exercise
Price
Per
Share
Weighted
Average
Exercise
Price
Weighted
Average
Remaining
Life
Aggregate
Intrinsic
Value
Outstanding, December 31, 2024 2,752,962  $ 0.71  $ 3.93  $ 1.14  6.70 years $ 1,348,684 
Granted 279,836  $ 2.14  $ 8.61  7.60 
Exercised (575,154) $ 0.71  $ 3.93  $ 1.21  2,144,534 
Canceled and forfeited (110,600) $ 0.71  $ 3.48  0.95 
Outstanding, December 31, 2025 2,347,044  $ 0.71  $ 8.61  $ 1.90  6.29 years $ 7,961,973 
Exercisable, December 31, 2025 1,490,958  $ 1.24  $ 5,517,036 
Vested and expected to vest, December 31, 2025 2,218,631  $ 1.84  $ 7,595,233 
Summary of Weighted Average Assumptions Used in Black-Scholes Option Pricing
The weighted average assumptions used in the Black-Scholes option pricing model for options granted in years ended December 31, 2025 and 2024 are as follows:
Stock option award assumptions: 2025 2024
Expected dividend yield —% —%
Expected life 6.25 years 6.25 years
Risk-free interest rate 4.46% 4.28%
Expected volatility 45.48% 40.17%