Note 17. Stock-Based Compensation

Stock Options

We have five stock incentive plans: the 2002 Stock Incentive Plan (the “2002 Plan”), the 2009 Stock Incentive Plan (the “2009 Plan”), the 2011 Stock Incentive Plan (the “2011 Plan”), the 2015 Omnibus Equity Incentive Plan (the “2015 Plan”), and the 2018 Omnibus Equity Incentive Plan (the “2018 Plan”) (collectively, the “Plans”). The 2002 Plan, the 2009 Plan, the 2011 Plan and the 2015 Plan (the “Prior Plans”) have been superseded by the 2018 Plan. In May 2018, the Company’s stockholders approved the 2018 Plan for issuances up to an aggregate of 3,730,179 shares plus 1,269,821 shares that were authorized but unissued under the Prior Plans as of the effective date of the 2018 Plan. In April 2021 and May 2024, the Company’s stockholders approved additional increases of 2,850,000 and 2,500,000 shares, respectively, authorized under the 2018 Plan. The Prior Plans will remain in effect until all awards granted under such Prior Plans have been exercised, forfeited, cancelled, or have otherwise expired or terminated in accordance with the terms of such awards, but no awards will be made pursuant to the Prior Plans after the effectiveness of the 2018 Plan. As of December 31, 2025, the Company had 2,437,831 shares available for future awards under the 2018 Plan.

During the years ended December 31, 2025, 2024 and 2023, we granted stock options at exercise prices equal to or greater than the quoted market price of our common stock on the grant date. The fair value of each option grant was estimated on the date of grant using Black-Scholes with the following weighted average assumptions:

December 31, 

  ​ ​ ​

2025

  ​ ​ ​

2024

  ​ ​ ​

2023

Expected life (years)

3.7 - 4.8

3.8 - 4.9

3.8 - 5.2

Risk-free interest rate

 

3.6% - 4.0%

3.5% - 4.5%

3.5% - 4.4%

Volatility

74.4% - 82.9%

68.9% - 74.9%

69.9% - 80.0%

Dividend yield

 

0%

0%

0%

The expected option life assumption is estimated based on the simplified method as the Company’s history is not indicative of future expected lives. Accordingly, the Company has utilized the average of the contractual term of the options and the weighted average vesting period for all options to calculate the expected option term. The risk-free interest rate assumption is based upon observed interest rates appropriate for the expected term of our employee stock options. The expected volatility is based on the average of the historical volatility and the implied volatility of our stock commensurate with the expected life of the stock-based award. We do not anticipate paying dividends on the common stock in the foreseeable future.

We recognize stock-based compensation cost on a straight-line basis over the vesting period. Stock-based compensation expense is recognized only for those awards that ultimately vest. Forfeitures are recorded when recognized.

Total stock-based compensation expense related to all of our share-based payment awards is comprised of the following (in thousands):

Years Ended December 31, 

  ​ ​ ​

2025

  ​ ​ ​

2024

  ​ ​ ​

2023

Cost of revenue

$

1,852

$

2,428

$

1,961

Selling, general and administrative

 

7,453

 

12,839

 

16,075

Engineering and development

 

761

 

1,300

 

1,787

$

10,066

$

16,567

$

19,823

A summary of stock option activity is as follows:

Weighted-

Weighted-

Average

Average

Remaining

Aggregate

Number of

Exercise

Contractual

Intrinsic

  ​ ​ ​

Shares

  ​ ​ ​

Price/Share

  ​ ​ ​

Term (Years)

  ​ ​ ​

Value (1)

Outstanding — December 31, 2022

 

7,340,521

$

15.10

 

  ​

 

  ​

Granted (weighted-average fair value of $11.86 per share)

 

432,990

20.63

 

  ​

 

  ​

Exercised

 

(407,814)

 

3.63

 

  ​

 

  ​

Forfeited

 

(140,877)

 

24.82

 

  ​

 

  ​

Outstanding — December 31, 2023

 

7,224,820

15.88

 

  ​

 

  ​

Granted (weighted-average fair value of $7.52 per share)

342,531

13.63

  ​

Exercised

 

(582,170)

 

4.79

 

  ​

 

Forfeited

 

(182,707)

 

28.47

 

  ​

 

Outstanding — December 31, 2024

6,802,474

$

16.38

Granted (weighted-average fair value of $4.18 per share)

523,684

6.94

Exercised

 

(888,307)

 

4.47

 

Forfeited

(433,573)

23.40

Expired

(304,834)

18.20

Outstanding — December 31, 2025

 

5,699,444

$

16.73

 

3.4

$

7,314

Vested (exercisable) — December 31, 2025

 

5,089,725

$

17.38

 

3.2

$

6,272

Expected to vest after December 31, 2025 (unexercisable)

 

609,719

$

11.33

 

5.7

$

1,042

(1)Aggregate intrinsic value represents the difference between the exercise price of the option and the closing market price of the Company’s common stock on December 31, 2025, (the last trading day of the year) which was $9.60 per share.

As of December 31, 2025, there was unrecognized compensation expense of $3.8 million related to unvested stock options, which we expect to recognize over a weighted average period of 2.0 years.

The total intrinsic value of options exercised during the years ended December 31, 2025, 2024 and 2023 was $2.3 million, $2.4 million and $6.7 million, respectively.

Restricted Stock Units

A summary of our restricted stock unit activity is as follows:

  ​ ​ ​

  ​ ​ ​

Weighted Average

Number of Restricted

Fair Value per

Stock Units

Share

Outstanding — December 31, 2022

727,984

$

38.32

Granted

667,319

19.8

Share issuance

(228,932)

37.63

Forfeited

(89,742)

29.34

Outstanding — December 31, 2023

1,076,629

$

27.73

Granted

460,599

14.26

Share issuance

(355,058)

30.04

Forfeited

(143,079)

23.14

Outstanding — December 31, 2024

 

1,039,091

$

21.75

Granted

 

689,893

 

6.51

Share issuance

 

(394,840)

 

25.67

Forfeited

 

(246,931)

 

17.26

Expired

(4,019)

6.41

Outstanding — December 31, 2025

 

1,083,194

$

11.45

For the years ended December 31, 2025, 2024 and 2023, we recorded stock-based compensation expense on our issued restricted stock units of $6.7 million, $10.7 million and $10.0 million, respectively. As of December 31, 2025, there was unrecognized compensation expense of $8.1 million related to unvested restricted stock units, which we expect to recognize over a weighted average period of 2.2 years.

Historical Timeline

Fiscal YearFiled
2025Mar 5, 2026Showing above
2024Mar 7, 2025
2023Mar 13, 2024

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.