v3.26.1
Equity Incentive Plan (Tables)
 3 Months Ended
Mar. 31, 2026
Equity [Abstract]  
Summary of Stock Option Activity

The following table summarizes the stock option activity for the three months ended March 31, 2026:

 

 

 

Shares
(in thousands)

 

 

Weighted-
Average
Exercise Price

 

 

Weighted-
Average
Remaining
Contractual
Term (Years)

 

Outstanding at December 31, 2025

 

 

28,705

 

 

$

2.98

 

 

 

7.64

 

Granted

 

 

219

 

 

$

1.14

 

 

 

 

Exercised

 

 

—

 

 

$

—

 

 

 

 

Expired and forfeited

 

 

(412

)

 

$

6.10

 

 

 

 

Outstanding at March 31, 2026

 

 

28,512

 

 

$

2.92

 

 

 

7.42

 

 
Summary of Fair Value of Option Grant on Grant Date and Employee Stock Purchase Plan Using Black-Scholes Option Pricing Model and Market Based Stock Option Grants Monte Carlo Simulation Model

We estimated the fair value of each option grant on the grant date using the Black-Scholes option pricing model and for market-based stock option grants using the Monte Carlo simulation model. The following are the weighted-average assumptions:

 

 

 

For the Three Months Ended

 

 

 

March 31,

 

 

 

2026

 

 

2025

 

Risk-free interest rate

 

 

3.9

%

 

 

4.3

%

Dividend yield

 

 

0.0

%

 

 

0.0

%

Volatility

 

 

79.8

%

 

 

80.1

%

Expected life (years)

 

6 to 10

 

 

6 to 10

 
Summary of Restricted Stock Unit Activity

The following table summarizes the restricted stock unit activity ("RSUs") for the three months ended March 31, 2026:

 

 

 

Shares
(in thousands)

 

 

Weighted-Average Grant Date Fair Value

 

Outstanding at December 31, 2025

 

 

3,799

 

 

$

1.91

 

Granted

 

 

7,947

 

 

$

1.32

 

Released

 

 

(302

)

 

$

1.89

 

Expired and forfeited

 

 

(104

)

 

$

1.54

 

Outstanding at March 31, 2026

 

 

11,340

 

 

$

1.50

 

 

The fair value of RSUs is estimated based on the closing market price of our common stock on the date of the grant. RSUs generally vest quarterly over a four-year period.

We estimated the fair value of each purchase right granted under our 1997 Employee Stock Purchase Plan, as amended, at the beginning of each new offering period using the Black-Scholes option pricing model. The following are the weighted average assumptions:

 

 

 

For the Three Months Ended

 

 

 

March 31,

 

 

 

2026

 

 

2025

 

Risk-free interest rate

 

 

3.8

%

 

 

4.9

%

Dividend yield

 

 

0.0

%

 

 

0.0

%

Volatility

 

 

71.3

%

 

 

95.3

%

Expected life (months)

 

 

6

 

 

 

6

 

 
Summary of Stock-Based Compensation Expense related to Stock-Based Payment Awards Granted

The following table summarizes stock-based compensation expense related to stock-based payment awards granted pursuant to all of our equity compensation arrangements (in thousands):

 

 

 

Three Months Ended
March 31,

 

 

 

 

2026

 

 

2025

 

 

Research and development

 

$

254

 

 

$

244

 

 

General and administrative

 

 

1,854

 

 

 

1,572

 

 

Sales and marketing

 

 

868

 

 

 

695

 

 

Total stock-based compensation expense

 

$

2,976

 

 

$

2,511