The Company maintains the 2016 Stock Incentive Plan and the 2021 Incentive Award Plan (the “Stock Plans”) under which incentive stock options, non-qualified stock options and RSUs may be granted to employees. Under the Stock Plans, the Company has 9,256,007 shares available for issuance as of December 31, 2021.

Under the terms of the Stock Plans, incentive stock options must have an exercise price at or above the fair market value of the stock on the date of the grant, while non-qualified stock options are permitted to be granted below fair market value of the stock on the date of grant. The majority of stock options granted have service-based vesting conditions only. The service-based vesting conditions vary though typically, stock options vest over four years with 25% of stock options vesting on the first anniversary of the grant and the remaining 75% vesting monthly over the remaining 36 months. Option holders have a ten-year period to exercise the options before they expire.

The following table summarized the stock option activity and related information under all stock option plans:


	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of January 1, 2019		5,738,520		$	0.17		9.01	$	2,620
Granted		7,089,185			0.29		—		—
Exercised		(243,780	)		0.14		—		—
Forfeited		(539,751	)		0.23		—		—
Expired		(130,394	)		0.24		—		—
Outstanding as of December 31, 2019		11,913,780		$	0.24		8.73	$	15,707
Granted		7,393,347			0.55		—		—
Exercised		(351,037	)		0.20		—		—
Forfeited		(1,006,417	)		0.40		—		—
Expired		(147,687	)		0.27		—		—
Outstanding as of December 31, 2020		17,801,986		$	0.36		8.27	$	140,560
Exercised		(3,701,243	)		0.25		—		—
Forfeited		(242,387	)		0.41		—		—
Expired		—			—		—		—
Outstanding as of December 31, 2021		13,858,356		$	0.39		7.47	$	99,406
Vested and exercisable as of December 31, 2021		9,678,341		$	0.33		7.24	$	69,986
Vested and expected to vest as of December 31, 2021		13,858,356		$	0.39		7.47	$	99,406

There were no options granted during the year ended December 31, 2021. The intrinsic value of options exercised during years ended December 31, 2021, 2020, and 2019 was $32.0 million, $4.8 million, and $0.3 million, respectively.

As of December 31, 2021, the Company had $5.0 million of unrecognized stock-based compensation expense related to the stock options. This cost is expected to be recognized over a weighted-average period of 1.9 years.

As of December 31, 2021, the Company recognized $1.1 million of the additional compensation expense for certain stock option grants that had a performance vesting condition that was satisfied as of the Closing of the BCA.

Beginning November 2020, the Company granted RSUs and PBRSUs to certain employees and consultants pursuant to the 2016 and 2020 Stock Plan. RSU’s expire in 10 years from the date of grant and typically vest 25 percent upon the one-year anniversary date from the initial vesting date, with 12.5% vesting on each six-month anniversary date over the following three years. The RSUs are subject to a time-based vesting condition and a performance condition tied to the completion of the merger with InterPrivate, both of which must be satisfied in order for the RSUs to be vested and settled for shares of Common Stock. The performance vesting condition for these RSU were met on March 12, 2021. As a result, the Company’s outstanding RSUs vested to the extent the applicable service condition was satisfied as of such date. The vesting of these outstanding RSUs resulted in approximately $2.7 million of incremental stock-based compensation expense for the year ended December 31, 2021.

The following table summarizes our RSU activity (includes performance-based restricted stock units) for the year ended December 31, 2021:


	Shares			Weighted Average Grant Date Fair Value per Share
Outstanding as of January 1, 2020		—		$	—
Granted		1,536,195			7.74
Released		—			—
Forfeited		—			—
Outstanding as of December 31, 2020		1,536,195		$	7.74
Granted		6,206,975			10.51
Released		(758,945	)		9.34
Forfeited		(353,146	)		9.83
Outstanding as of December 31, 2021		6,631,079		$	10.04

The total fair value of restricted stock and performance based restricted stock awards vested for the years ended December 31, 2021, was $6.6 million. There were no RSU's grated prior to 2020.

As of December 31, 2021, the Company had $55.3 million of unrecognized stock-based compensation expense related to the RSUs. This cost is expected to be recognized over a weighted average period of 3.0 years.

Restricted stock activity for the year ended December 31, 2020 and December 31, 2019 is as follows:


	Shares			Weighted Average Grant Date Fair Value per Share
Outstanding as of January 1, 2019		34,878,713		$	0.03
Granted		—			—
Forfeited		—			—
Vested		(17,439,359	)		0.03
Outstanding as of December 31, 2019		17,439,354		$	0.03
Granted		—			—
Forfeited		—			—
Vested		(17,439,354	)		0.03
Outstanding as of December 31, 2020		—		$	—

There were no restricted stock granted during the years ended December 31, 2021, 2020 and 2019.

Total stock-based compensation expense by function was as follows (in thousands):


	Year ended December 31,
	2021		2020		2019
Cost of Revenue	$	1,483	$	470	$	32
Research and development expenses		12,754		1,895		1,235
Sales and marketing expenses		371		26		17
General and administrative expenses		7,629		1,415		869
Total	$	22,237	$	3,806	$	2,153