In March 2015, the Company adopted the 2015 Equity Incentive Plan (the “2015 Plan”). The 2015 Plan replaces the Company’s prior 2000 Equity Incentive Plan (the “2000 Plan”) and the 2006 Equity Incentive Plan (the “2006 Plan”) (collectively, the “Plans”). Beginning March 2015, all awards were granted under the 2015 Plan. In addition, any awards that were previously granted under any prior Plans that terminate without issuance of shares, shall be eligible for issuance under the 2015 Plan.

Under the 2015 Plan, the Company may grant to its employees, outside directors and consultants awards in the form of non-qualified stock options, shares of restricted stock, stock units, or stock appreciation rights and performance shares. The Company’s Board of Directors administers the Plan and is responsible for determining the individuals to be granted options or shares, the number of options or shares each individual will receive, the price per share and the exercise period of each option.

On December 15, 2017, the Compensation Committee adopted the 2017 New Hire Equity Incentive Plan (“2017 New Hire Plan”), which is intended to be exempt from the stockholder approval requirements under the “inducement grant exception” provided by the Inducement Rule. The Committee authorized the issuance of up to 1.5 million Common Shares to new hires, with the purpose of promoting the long-term success of the Company and the creation of stockholder value by (a) providing for the attraction and retention of new employees with exceptional qualifications, (b) encouraging new employees to focus on critical long-range objectives, and (c) linking new employees directly to stockholder interests through increased stock ownership. As required by the Inducement Rule, the Company issues a press release promptly upon issuing shares to new employees pursuant to the 2017 New Hire Plan.

There were no significant changes to the Company’s Stock Plans during the year ended December 31, 2020. As of December 31, 2020, there were 1.5 million shares available for the grant or award under the Company’s 2015 Plan and 0.4 million shares available for the grant or award under the Company’s 2017 New Hire equity incentive Plan.

The Company’s performance cash awards granted to executives under the Long Term Incentive (“LTI”) Plans have been accounted for as liability awards, due to the Company’s intent and the ability to settle such awards in cash upon vesting and has reflected such awards in accrued expenses. As of December 31, 2020, the liability for such awards is approximately $0.5 million.


	Twelve Months Ended December 31,
		2020		2019		2018
Cost of revenues		$	2,409	$	2,929	$	4,370
Research and development		4,380		4,227		6,055
Selling, general and administrative		4,348		15,094		17,179
Total stock-based compensation expense		$	11,137	$	22,250	$	27,604


	Twelve Months Ended December 31,
		2020		2019		2018
Stock options		$	1,308	$	7,348	$	7,368
Restricted stock awards		9,743		14,775		20,216
Performance Based Cash Units		86		127		20

Total stock-based compensation before taxes		11,137		22,250		27,604
Tax benefit		$	1,815	$	3,455	$	5,387

The total stock-based compensation cost related to unvested equity awards as of December 31, 2020 was approximately $12.8 million. The expense is expected to be recognized over a weighted-average period of approximately 0.8 years.

The total stock-based compensation cost related to unvested performance-based cash units as of December 31, 2020 was approximately $0.3 million. The expense is expected to be recognized over a weighted-average period of approximately 1.6 years.

Options that were granted under the Company’s 2000, 2006 and 2015 Plans generally vest 25% on the first-year anniversary of the date of grant plus an additional 1/48th for each month of continuous service thereafter.

Options that were granted under the Company’s 2010 Plan generally vest 50% on the second-year anniversary and an additional 1/48th for each month of continuous service thereafter.

Incentive options that were granted under the 2000 and 2006 Plans generally vest 25% on the first-year anniversary on the date of grant and an additional 1/48th for each month of continuous service thereafter.

The Company uses the Black-Scholes option pricing model for determining the estimated fair value for stock options. The weighted-average assumptions used in the Black-Scholes option pricing model are as follows:


	Twelve Months Ended December 31,
		2020			2019			2018
Expected stock price volatility		74.5		%	69.6		%	65.5		%
Risk-free interest rate		1.0		%	1.9		%	2.6		%
Expected life of options (in years)		4.47			4.34			4.13
Expected dividend yield		0.0		%	0.0		%	0.0		%
Weighted-average fair value (PSV) of the options		$	2.79		$	3.82		$	4.91


Options	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding at December 31, 2019	4,922	$	14.54
Options Granted	2,315	4.84
Options Exercised	—	—
Options Cancelled	(2,814)	14.32
Outstanding at December 31, 2020	4,423	$	9.60	4.57	$	788,413.19
Vested at December 31, 2020	1,809	$	15.38	2.59	$	—
Exercisable at December 31, 2020	1,809	$	15.38	2.59	$	1,547.85

The total intrinsic value of stock options exercised during the year ended December 31, 2020 and 2019 was nil and $20.5 thousand, respectively. The total intrinsic value of stock options exercisable as of December 31, 2020 and 2019 was $1.5 thousand and $1.2 thousand, respectively.

Restricted stock awards (“Restricted Stock”) granted under the Company’s Plans generally vest 25% of the applicable shares on the first anniversary of the date of grant and thereafter an additional 1/16th for each three months of continuous service.

Generally, performance stock awards granted under the Company’s 2015 Plan vest at the end of a three-year period based on service and achievement of certain performance objectives determined by the Company’s Board of Directors.


Unvested Restricted Stock	Number of Awards	Weighted- Average Grant Date Fair Value
Unvested at December 31, 2019	3,375	$	8.68
Granted	301	4.90
Vested	(1,341)	9.11
Forfeited	(825)	7.79
Unvested at December 31, 2020	1,510	$	7.05

Restricted stock awards are granted subject to other service conditions or service and performance conditions (“Performance-Based Awards”). Restricted stock and Performance-Based Awards are measured at the closing stock price at the date of grant and are recognized straight line over the requisite service period.

Performance based cash units (PBCU) generally vest at the end of a three-year period based on service and achievement of certain performance objectives determined by the Company’s Board of Directors. The PBCU can be settled in cash or in equity as determined by the Compensation Committee.


Unvested Cash Units	Number of Awards	Period end Fair Value
Unvested at December 31, 2019	1,046	$	4.75
Granted	1,391	—
Vested	—	—
Forfeited	(1,530)	—
Unvested at December 31, 2020	907	$	4.70

Performance based cash units are measured at the closing stock price at the reporting period end date and are recognized straight line over the requisite service period. The expense for the period will increase or decrease based on updated fair values of these awards as well as the percentage achievement of the performance metrics at each reporting date.