Stock Option Plan

9 Months Ended

Sep. 30, 2020

Share-based Payment Arrangement [Abstract]

In September 2019, the Company's Board of Directors adopted, and the Company's stockholders approved, the 2019 Incentive Award Plan (the 2019 Plan). A total of (i) 2,011,832 shares of common stock plus (ii) shares subject to awards granted under the 2013 Plan on or before the effective date of the 2019 Plan became available for issuance under the 2019 Plan and was initially reserved for issuance under the 2019 Plan. Under the 2019 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and other awards to individuals who are then employees, officers, non-employee directors or consultants of the Company or its subsidiaries. The options generally expire ten years after the date of grant and are exercisable to the extent vested. Vesting is established by the Board of Directors and is generally four years from the date of grant. As of September 30, 2020, 1,140,029 shares remained available for future awards.

Activity under the Company's stock option plans is set forth below:


	Number of Options	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding, December 31, 2019	1,375,542	$	8.33	9.16	$	23,654
Granted	901,531	$	16.14
Exercised	(47,354)	$	0.27
Forfeited	(244,749)	$	10.05
Expired	(9,720)	$	29.11
Outstanding, September 30, 2020	1,975,250	$	11.77	8.94	$	5,064
Vested and expected to vest, September 30, 2020	1,975,250	$	11.77	8.94	$	5,064
Options exercisable, September 30, 2020	394,739	$	6.51	8.25	$	2,430

The intrinsic value is calculated as the difference between the fair value of the Company's common stock and the exercise price of the stock options.

Stock-Based Compensation Expense

The fair value of employee stock options was estimated using the following assumptions to determine the fair value of stock options granted:


	Three Months Ended September 30,		Nine Months Ended September 30,
	2020	2019	2020	2019
Expected volatility	52%	59%	47%-52%	59%
Risk-free interest rate	0.4%	2.0%	0.4%-1.7%	2.0%-2.6%
Dividend yield	—	—	—	—
Expected term (in years)	6.08	5.75-6.08	5.50-6.08	5.75-6.08

Total non-cash stock-based compensation expense recorded related to options granted in the condensed statement of operations is as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Cost of revenue	$	9	$	4	$	21	$	6
Selling, general and administrative	710		55		1,696		73
Research and development	80		3		160		6
Total	$	799	$	62	$	1,877	$	85

Stock-based compensation expense for the ESPP was immaterial for the three and nine months ended September 30, 2020.

As of September 30, 2020, total unrecognized compensation cost was $9.3 million, which is expected to be recognized over a remaining weighted-average vesting period of 3.0 years.