The Company has authorized 5.0 million shares of preferred stock, par value $0.0001, none of which is issued and outstanding.

Each share of common stock has the right to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the Board of Directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. No dividends have been declared or paid as of December 31, 2020.

On November 14, 2019, the Company's Board of Directors authorized the repurchase of up to $10.0 million of its outstanding shares of common stock. As of December 31, 2020, no repurchases had been executed under the program.

As of December 31, 2020, there were approximately 3.0 million shares available for issuance under the Company's equity incentive plan. The Company has granted restricted stock awards and units during the years ended December 31, 2020 and 2019, and has not granted any stock options or stock appreciation rights during the same periods.

Restricted stock award (RSA) and restricted stock unit (RSU) activity under the Company's equity incentive plan was as follows (in thousands, except weighted-average grant date fair values):


		Number of Restricted Stock Awards	Weighted-Average Grant Date Fair Value
RSAs at December 31, 2019		459	$	20.49
	Awards granted	310	22.54
	Awards vested	(116)	21.41

RSAs at December 31, 2020		653	$	21.30


		Number of Restricted Stock Units	Weighted-Average Grant Date Fair Value
RSUs at December 31, 2019		2,407	$	19.47
	Awards granted	1,187	21.89
	Awards vested	(689)	19.17
	Awards forfeited	(105)	20.24
RSUs at December 31, 2020		2,800	$	20.54

The total grant date fair value of RSAs and RSUs vested during the year ended December 31, 2020 was $2.5 million and $13.2 million, respectively. Awards outstanding as of December 31, 2020 include 0.7 million performance-based awards that will vest upon meeting certain performance criteria.

The following table summarizes the Company’s stock option activity during the year ended December 31, 2020 (in thousands, except weighted-average exercise prices):


	Number of Options	Weighted-Average Exercise Price	Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding, December 31, 2019	4,239	$1.54	6.1	$79,443

Options exercised	(862)	$1.60
Options canceled	(19)	$1.51
Outstanding, December 31, 2020	3,358	$1.53	5.3	$104,510
Options exercisable at December 31, 2020	2,752	$1.11	5.0	$86,784
Options vested as of December 31, 2020 and expected to vest after December 31, 2020	3,358	$1.53	5.3	$104,510

Total intrinsic value of options exercised for the years ended December 31, 2020 and 2019 was $17.0 million and $15.8 million, respectively. The Company received proceeds of $1.4 million and $1.6 million from the exercise of options for the years ended December 31, 2020 and 2019, respectively.

Information related to activity under the Company's Employee Stock Purchase Plan (ESPP) was as follows (in thousands, except weighted-average per share prices):


	Year Ended December 31, 2020
Shares issued	78
Weighted-average per share purchase price	$	17.85
Weighted-average per share discount from the fair value of our common stock on date of issuance	$	3.15

Total stock-based compensation expense was included in our consolidated statements of operations as follows (in thousands):


	Year Ended December 31,
		2020		2019		2018
Cost of revenues		$	1,621	$	1,201	$	456
Research and development		9,703		3,299		1,293
Sales, general and administrative		14,140		5,230		3,056
		$	25,464	$	9,730	$	4,805

As of December 31, 2020, total unrecognized stock-based compensation related to unvested stock awards was $62.4 million, which will be recognized over the next five years as follows (in thousands):

Total unrecognized stock-based compensation includes approximately 0.6 million awards that do not have a measurement date and have been valued as of December 31, 2020.