Stock-based Compensation (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2020

Dec. 31, 2019

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of fair value of each option grant estimated using black-scholes option-pricing model

The fair value of stock option awards was determined on the grant date using the Black-Scholes valuation model based on the following assumptions:

	9/30/2020		12/31/2019
Expected term (years) (1)		5.96 — 6.02		5.27 — 6.02
Common stock (price per share)	$	22.80 —$ 76.93	$	17.38 —$ 22.80
Expected volatility (2)		49.3% — 51.9%		44.6% — 49.3%
Risk-free interest rate (3)		0.4% — 1.8%		1.6% — 1.9%
Dividend yield (4)		0%		0%

(1) The 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) Volatility, or the standard deviation of annualized returns, was calculated based on comparable companies’ report volatilities.

(3) Risk free rate was obtained from US treasury notes for the expected terms noted as of the valuation date.

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

The fair value of stock option awards in 2019 was determined on the grant date using the Black-Scholes valuation model based on the following assumptions:

	2019
Expected term (years) (1)		5.27 – 6.02
Current stock value	$	17.38 – 22.80
Expected volatility (2)		44.6% – 49.3%
Risk-free interest rate (3)		1.6% – 1.9%
Dividend yield (4)		0%

(1) The 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) Volatility, or the standard deviation of annualized returns, was calculated based on comparable companies’ reported volatilities.

(3) Risk free rate was obtained from US treasury notes for the expected terms noted as of the valuation date.

(4) The Company has assumed a dividend yield of zero as it has no plans to declare dividends in the foreseeable future.

Summary of stock options

A summary of the Company’s stock option activity for nine months ended September 30, 2020 is as follows:

	Number of Common Stock options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (In Thousands)
Outstanding as of December 31, 2019		365,938		$	22.73		9.76	$	22
Granted		921,721			22.73		—		—
Exercised		—					—		—
Forfeited		(87,685	)		22.73		—		—
Expired		—			—		—		—
Outstanding as of September 30, 2020		1,199,974		$	22.73		9.32	$	141,657
Vested and exercisable as of September 30, 2020		59,538		$	22.73		9.06	$	7,028
Vested and expected to vest as of September 30, 2020		1,199,974		$	22.73		9.32	$	141,657

A summary of the Company’s stock option activity for years ended 2019 and 2018 is as follows:

	Number of Common Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (In Thousands)
Outstanding as of January 1, 2019		—		$	—		—	$	—
Granted		366,988			22.73		9.76
Exercised		—			—		—
Forfeited		(1,050	)		22.73		9.61
Expired		—			—		—
Outstanding as of December 31, 2019		365,938			22.73		9.76		22
Vested and exercisable as of December 31, 2019		26,035			22.73		9.75		2
Vested and expected to vest as of December 31, 2019		365,938		$	22.73		9.76	$	22

Summary of non-employee restricted stock activity

Non-employee restricted stock activity for the nine months ended September 30, 2020 is as follows:

	Shares			Weighted Average Grant Date Fair Value per Share
Outstanding as of December 31, 2019		1,999		$	17.61
Granted		—			—
Exercised		—			—
Forfeited		—			—
Vested		(1,375	)		17.61
Outstanding as of September 30, 2020		624		$	17.61

Non-employee restricted stock activity for years ended 2019 and 2018 is as follows:

	Shares			Weighted Average Grant Date Fair Value per Share
Outstanding as of December 31, 2017		37,989		$	0.05
Granted		2,800			13.75
Forfeited		(625	)		0.05
Vested		(22,946	)		0.64
Outstanding as of December 31, 2018		17,218			1.46
Granted		—			—
Forfeited		—			—
Vested		(15,219	)		17.61
Outstanding as of December 31, 2019		1,999		$	17.61

Summary of stock-based compensation expense by function

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

	Nine Months ended September 30,
	2020		2019
Cost of sales	$	237	$	69
Research and development		1,608		616
Sales and marketing		334		107
General and administrative		2,531		1,064
Total	$	4,710	$	1,856

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

	Year Ended December 31,
	2019		2018
Cost of sales	$	92	$	66
Research and development		914		564
Sales and marketing		163		83
General and administrative		1,533		1,349
Total	$	2,702	$	2,062

Restricted Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of stock options

Employee restricted stock activity for the nine months ended September 30, 2020 is as follows:

	Shares			Weighted Average Grant Date Fair Value per Share
Outstanding as of December 31, 2019		458,257		$	10.92
Granted		—			—
Forfeited		(113,776	)		11.37
Vested		(183,556	)		10.45
Outstanding as of September 30, 2020		160,925		$	13.88

Employee restricted stock activity for years ended 2019 and 2018 is as follows:

	Shares			Weighted Average Grant Date Fair Value per Share
Outstanding as of December 31, 2017		3,534,436		$	0.36
Granted		509,379			12.39
Forfeited		(89,047	)		2.50
Vested		(2,278,495	)		0.78
Outstanding as of December 31, 2018		1,676,273			3.01
Granted		150,800			17.54
Forfeited		(97,150	)		7.19
Vested		(1,271,666	)		1.97
Outstanding as of December 31, 2019		458,257		$	10.92