In December 2004, the Company’s stockholders approved the Omnibus Stock Option Plan. Authorized shares in this plan were 5,500,000. As of December 31, 2021, there were 3,465,001 options exercised during the life of the plan and 474,999 options remain outstanding. The 2004 Omnibus Stock Option Plan has been replaced by the 2012 Omnibus Equity Incentive Plan, so no further options are available for grant.

In December 2012, the Company’s stockholders approved the Company’s 2012 Omnibus Equity Incentive Plan to replace all prior plans (“Prior Plans”). The Prior Plans remain in effect until all awards granted under those plans have been exercised, forfeited, canceled, expired or otherwise terminated. In connection with the approval of such plan, all stock options, totaling 1,677,500 formerly available for new awards under the Prior Plans were transferred to the 2012 Omnibus Equity Incentive Plan.

During the Company's Annual Meeting of Stockholders, stockholders approved amendments to the Company's 2012 Omnibus Equity Incentive Plan increasing the number of shares of common stock reserved and available for grant by 4,000,000 in May 2014, 2,000,000 in May 2017, 3,000,000 in March 2019 and 4,000,000 in May 2020, resulting in a total of 14,677,500 reserved shares.

Stock options granted under this plan vest in a range from immediate to five years while generally stock options under this plan vest over five years. RSUs granted under this plan vest in a range from immediate to five years while generally RSUs under this plan vest over three years. Stock grants granted under this plan vest immediately.

As of December 31, 2021, there were 1,614,598 options exercised and 942,953 RSUs, performance awards and stock grants issued, during the life of the plan. There were 8,807,723 shares underlying these equity awards outstanding, leaving 3,312,226 available for grant.


	Number of Shares	Weighted Average Exercise Price per Share
Options Outstanding January 1, 2020	10,132,562	$	12.28
Granted	1,738,083	8.53
Forfeited	(713,070)	14.23
Exercised	(2,631,935)	2.30
Expired	(480,179)	18.62
Options Outstanding December 31, 2020	8,045,461	14.18
Granted	489,804	7.09
Forfeited	(370,106)	14.04
Exercised	(426,762)	3.79
Expired	(545,857)	19.85
Options Outstanding December 31, 2021	7,192,540	13.89
Exercisable December 31, 2021	4,865,369	14.44

The cash received from the exercise of options during the year ended December 31, 2021 was $1.6 million and the tax benefit realized was zero for the same period. Upon exercise, shares are issued from shares authorized and held in reserve. The intrinsic value of options exercised was $3.3 million, $23.5 million and $2.3 million for the years ended December 31, 2021, 2020 and 2019, respectively.

The Company accounts for all option grants using the Black-Scholes option pricing model. The table below summarizes the inputs used to calculate the estimated fair value of options awarded for the years ended December 31:


	2021			2020			2019
Expected term (in years)	5.79			5.94			6.28
Volatility	65		%	58		%	60		%
Expected dividends	—			—			—
Risk free interest rates	1.1		%	0.6		%	2.1		%
Estimated forfeitures	—		%	—		%	—		%
Weighted average fair value	$	4.09		$	4.49		$	8.33


	Options Outstanding		Options Exercisable
Number of options	7,192,540		4,865,369
Weighted average remaining contractual term (in years)	5.69		4.69
Weighted average exercise price	$	13.89	$	14.44
Weighted average fair value	$	8.64	$	8.91
Aggregate intrinsic value (in millions)	$	1.5	$	1.5

The aggregate intrinsic value in the table above represents the total pretax intrinsic value that would have been received by the option holders had all option holders exercised their options on that date. It is calculated as the difference between the Company’s closing stock price of $5.22 on the last trading day of 2021 and the exercise price multiplied by the number of shares for options where the exercise price is below the closing stock price. This amount changes based on the fair value of the Company’s stock.


	Number of Shares	Weighted Average Grant Date Fair Value per Share
RSUs & Stock Grants Outstanding January 1, 2020	14,332	$	16.66
Granted	813,256	11.44
Forfeited	(98,398)	11.66
Vested/released	(202,776)	12.41
RSUs & Stock Grants outstanding December 31, 2020	526,414	11.17
Granted	2,704,948	11.23
Forfeited	(479,472)	11.01
Vested/released	(661,708)	12.23
RSUs & Stock Grants outstanding December 31, 2021	2,090,182	10.77

The total fair value of RSUs and stock grants vested and released during the period was $8.1 million, $2.7 million, and $0.2 million for the years ending December 31, 2021, 2020 and 2019, respectively.

The Company records compensation cost based on the fair value of the award. The table below summarizes the weighted average fair value of RSUs and stock grants awarded for the years ending December 31:

The expense and tax benefits recognized on the Company’s consolidated statements of operations and comprehensive loss related to share-based compensation for the years ended December 31 (in thousands) is as follows:


	2021		2020		2019
Cost of Sales	$	325	$	351	$	277
Research and development	4,102		4,035		4,115
Sales, general and administrative	17,620		12,078		8,226
Total equity-based compensation expense	$	22,047	$	16,464	$	12,618
Recognized tax benefit	$	—	$	—	$	—

The share-based compensation cost capitalized to inventory or inventory transferred to property and equipment (also referred to as instruments) for the years ended December 31 (in thousands) is as follows:

As of December 31, 2021, unrecognized equity-based compensation cost related to unvested stock options, and unvested RSUs was $5.3 million and $11.6 million, respectively. This is expected to be recognized over the years 2022 through 2026.

Included in the above-noted stock options outstanding and stock compensation expense are performance-based stock options which vest only upon the achievement of certain targets. Performance-based stock options are generally granted at-the-money, contingently vest over a period of 1 to 2 years, depending on the nature of the performance goal, and have contractual lives of 10 years. These options were valued in the same manner as the time-based options, with the assumption that performance goals will be achieved. The inputs for expected volatility, expected dividends, and risk-free rate used in estimating those options’ fair value are the same as the time-based options issued under the plan. The expected term for performance-based stock options is 5 to 7 years. However, the Company only recognizes stock compensation expense to the extent that the targets are determined to be probable of being achieved, which triggers the vesting of the performance options.

During 2018, the Company granted 225,000 performance-based stock options. Of these performance-based stock options performance obligations had been met for 75,000 options which became exercisable in a prior period. The remaining 150,000 options were forfeited due to the performance targets not being achieved in prior periods. During the year ended December 31, 2021, 75,000 performance-based stock options expired as they weren't exercised. Of these performance-based stock options, none were outstanding as of December 31, 2021.

During 2020, the Company granted another 105,000 performance-based stock options. Of these performance-based stock options, performance obligations had been met for 90,000 options which became exercisable. This included 45,000 performance-based stock options which vested during the year ended December 31, 2021, and the remaining 45,000 performance-based stock options vesting during the prior year. During the year ended December 31, 2021, 15,000 performance-based stock options were forfeited due to the performance targets not being achieved. Of these performance-based stock options, 90,000 were outstanding and exercisable as of December 31, 2021.

Included in the above-noted RSU outstanding amount are performance-based RSUs which vest only upon the achievement of certain targets. Performance-based RSUs contingently vest over a period of 1 to 3 years, depending on the nature of the performance goal, and have contractual lives of 10 years. These units were valued in the same manner as other RSUs, based on the published closing market price on the day before the grant date. However, the Company only recognizes stock compensation expense to the extent that the targets are determined to be probable of being achieved, which triggers the vesting of the performance options.

During 2020, the Company granted 364,338 performance-based RSUs. During the year ended December 31, 2021 and 2020, 84,000 and 81,000, of these performance-based RSUs were released due to the performance obligations being achieved, respectively. During the year ended December 31, 2021 and 2020, 9,369 and 23,995 of these performance-based RSUs were forfeited, respectively, due to performance obligations not being achieved or employees separating from the Company. Of these performance-based RSUs, 165,974 of these were outstanding as of December 31, 2021.

During 2021, the Company granted 233,472 performance-based RSUs. None of these performance-based RSUs have been released. During the year ended December 31, 2021, 121,666 performance-based RSUs were forfeited for performance obligations not being achieved or employees separating from the Company. Of these performance-based RSUs, 111,806 of these were outstanding as of December 31, 2021.