STOCK-BASED COMPENSATION
In 2018, our stockholders approved the adoption of the SenesTech, Inc. 2018 Equity Incentive Plan (the “2018 Plan”). The 2018 Plan has since been amended and restated on certain occasions, most recently on June 23, 2023, when our stockholders approved an increase to the total number of authorized shares to 207,071 shares.
Stock options are generally issued with a per share exercise price equal to the fair market value of our common stock at the date of grant. Options granted generally vest immediately, or ratably over a three- to 36-month period coinciding with their respective service periods, with terms of up to ten years. Certain stock option awards provide for accelerated vesting upon a change in control.
As of December 31, 2024, we had 60,228 shares of common stock available for issuance under the 2018 Plan.
Stock Options
We measure the fair value of stock options with service-based vesting criteria to employees, directors and consultants on the date of grant using the Black-Scholes option pricing model. The Black-Scholes valuation model requires us to make certain estimates and assumptions, including assumptions related to the expected price volatility of our stock, the expected period during which the options will be outstanding, the rate of return on risk-free investments, and the expected dividend yield for our stock.
Fair value of options granted is determined using the Black-Scholes option-pricing model with the following weighted average assumptions:
20242023
Risk-free interest rate3.8 %5.3 %
Expected dividend yield— %— %
Expected volatility128 %128.0 %
Expected term (in years)10.05.0
The weighted average fair value of options granted during the years ended December 31, 2024 and 2023 was $2.73 and $148.80 per share, respectively. The risk-free interest rate is estimated using treasury bill interest rates. The expected dividend yield is zero as we have not paid any dividends to date and do not expect to pay dividends in the future. Expected volatility is estimated based on the historical volatility of our common stock over the expected term as this represents our best estimate of future volatility. We use the “simplified method” to estimate expected term. Under the simplified method, an option’s expected term is calculated as the time until expiration.
The stock option activity consists of the following:
Number of
Options
Weighted
Average
Exercise
Price Per
Share
Weighted
Average
Remaining
Contractual
Term
(years)
Aggregate
Intrinsic
Value (1)
Outstanding as of December 31, 20222,314$2,040.00 3.9$— 
Granted1,661150.00 5.0— 
Exercised— — 
Forfeited(328)— — 
Expired(2)— — 
Outstanding as of December 31, 20233,6451,197.00 4.0— 
Granted144,2042.83 9.6— 
Exercised— — 
Forfeited(224)— — 
Expired(9)— — 
Outstanding as of December 31, 2024147,61627.13 9.5— 
Exercisable as of December 31, 202420,634
(2)
124.42 8.8— 
(1)
Calculated based on the difference between the estimated fair value of our stock and the exercise price of the underlying option. The estimated stock values used in the calculation was $2.83 and $150.00 per share for the years ended December 31, 2024 and 2023, respectively.
(2)
Includes options related to 603 shares that are inducement awards and not granted under the 2018 Plan.
As of December 31, 2024, the unrecognized stock-based compensation cost was $340,000, which is expected to be recognized over a weighted average period of 1.7 years.
Restricted Stock Units
The restricted stock unit activity consists of the following:
Number of
Units
Weighted Average
Grant Date Fair Value Per Unit
Outstanding as of December 31, 2022156$325.20 
Granted— 
Vested(156)325.20 
Forfeited— 
Outstanding as of December 31, 2023— 
Granted— 
Vested— 
Forfeited— 
Outstanding as of December 31, 2024— 
The stock-based compensation expense was recorded as following (in thousands):
Years Ended December 31,
20242023
Research and development$13 $17 
General and administrative313 538 
(1)
Total stock-based compensation expense$326 $555 
(1)
Includes $100,000 related to stock issued in exchange for marketing services.

Historical Timeline

Fiscal YearFiled
2024Mar 13, 2025Showing above
2021Mar 29, 2022
2020Mar 29, 2021

About Stock Compensation Disclosures

Stock-based compensation disclosures detail the equity awards granted to employees and executives — including stock options, restricted stock units (RSUs), and performance shares — along with the valuation methods and assumptions used to expense them. This section reveals the true cost of talent retention and the alignment between management incentives and shareholder interests.

Key signals: total unrecognized compensation expense and its expected recognition period signal future earnings headwinds from already-granted awards. For stock options, examine Black-Scholes assumptions — expected volatility, risk-free rate, and expected term — as understating any of these reduces reported compensation expense. Compare stock compensation expense as a percentage of revenue against peers to assess dilution cost. Watch vesting schedules for acceleration clauses tied to change-of-control events. Performance-based awards with undemanding targets may indicate weak governance. Add back stock compensation to operating cash flow to calculate a more conservative free cash flow figure.