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 3,500,763 shares available for issuance as of June 30, 2022.

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 fair value of stock option awards was determined on the grant date using the Black-Scholes option-pricing model. No new options were granted during the period ended June 30, 2021. The assumptions for the Black-Scholes model for options granted during the period ended June 30, 2022, were as follows:


	Six Months Ended June 30,
	2022	2021
Expected term (years)(1)	6.02	5.79 — 6.02
Expected volatility(2)	48.7% — 49.0%	43.5% — 44.6%
Common stock value	2.92 — 3.28	14.32 — 14.50
Risk-free interest rate(3)	2.73% — 2.93%	1.20% — 1.60%
Dividend yield(4)	0%	0%

(1)

Expected term is the length of time the grant is expected to be outstanding before it is exercised or terminated. This number is calculated as the midpoint between the vesting term and the original contractual term (contractual period to exercise). If the option contains graded vesting, then the vesting term would be based on the vesting pattern.

(2)

Expected volatility was estimated based on comparable companies' reported volatilities.

(3)

The risk-free rate is an interpolation of yields on U.S. Treasury securities with maturities equivalent to the expected term.

(4)

The Company has assumed a dividend yield of zero as they have no plans to declare dividends in the foreseeable future.

A summary of the Company’s stock option activity for six months ended June 30, 2022, is as follows:


	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2021		13,858,356		$	0.39		7.47	$	99,406
Granted		1,335,000			3.08		—		—
Exercised		(1,199,321	)		0.20		—		—
Forfeited		(134,221	)		0.48		—		—
Outstanding as of June 30, 2022		13,859,814			0.66		7.34		34,300
Vested and exercisable as of June 30, 2022		9,697,099			0.40		6.95		26,453
Vested and expected to vest as of June 30, 2022		13,859,814			0.66		7.34		34,300

The Company had $5.4 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 2.0 years.

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 three and six months ended June 30, 2021.

The following table summarizes our RSU activity which includes performance-based RSUs for the six months ended June 30, 2022:


	Shares			Weighted Average Grant Date Fair Value per Share
Outstanding as of December 31, 2021		6,631,079		$	10.04
Granted		5,353,145			3.56
Released		(1,130,020	)		10.26
Forfeited		(798,680	)		10.25
Outstanding as of June 30, 2022		10,055,524		$	6.55

As of June 30, 2022, the Company had $55.4 million of unrecognized stock-based compensation expense related to the RSUs. This cost is expected to be recognized over a weighted-average period of 3.1 years.

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


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Cost of revenue	$	206	$	410	$	342	$	410
Research and development expenses		4,652		2,022		8,975		3,818
General and administrative expenses		1,275		1,496		2,504		4,192
Sales and marketing expenses		301		81		397		102
Total	$	6,434	$	4,009	$	12,218	$	8,522