Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2020

Equity [Abstract]

Schedule of Reserved Shares of Common Stock for Issuance

As of September 30, 2020, the Company had reserved shares of common stock for issuance as follows (in thousands):

	As of
	September 30, 2020
Common stock awards granted under equity incentive plans		14,229
Common stock awards available for issuance under the 2017 Employee Stock Purchase Plan*		5,089
Common stock awards available for issuance under the 2017 Equity Incentive Plan		21,437
Total reserved shares of common stock		40,755

* The Company has not issued any common stock pursuant to the 2017 Employee Stock Purchase Plan.

Summary of Restricted Stock Unit Activity

Restricted stock unit activity for the nine months ended September 30, 2020 is as follows (in thousands, except per share data):

	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Balance, December 31, 2019 - outstanding		4,544		$	67.30
Awarded		1,286			137.52
Released		(898	)		65.89
Forfeited		(283	)		71.73
Balance, September 30, 2020 - outstanding		4,649		$	86.73

Schedule of Stock Option Activity

The following table summarizes the Company’s stock option activities under the 2008 Plan and 2017 Plan (in thousands, except per share data):

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Weighted Average Grant Date Fair Value Per Share		Aggregate Intrinsic Value
Balance, December 31, 2019 - outstanding		11,124		$	14.84		6.2		—
Granted		596			144.60		—	$	54.22
Exercised		(2,089	)		5.37		—		—
Forfeited and expired		(51	)		8.36		—		—
Balance, September 30, 2020 - outstanding		9,580		$	25.01		5.9		—	$	1,569,042
									—
Options exercisable at September 30, 2020		6,405		$	7.39		5.0		—	$	1,162,018

Summary of Stock-based Compensation Expense

The following table shows total stock-based compensation expense for the three and nine months ended September 30, 2020 and 2019 (in thousands):

	Three Months Ended				Nine Months Ended
	September 30, 2020		September 30, 2019		September 30, 2020		September 30, 2019
Cost of platform revenue	$	206	$	120	$	649	$	238
Cost of player revenue		362		287		1,010		776
Research and development		14,873		10,230		41,476		28,020
Sales and marketing		11,572		6,415		31,244		16,555
General and administrative		7,894		5,566		20,969		13,564
Total stock-based compensation	$	34,907	$	22,618	$	95,348	$	59,153

Summary of Assumptions Used to Value Stock-Based Awards Granted

The fair value of options granted under the equity incentive plans is estimated on the grant date using the Black-Scholes option-valuation model. The assumptions used in the Black-Scholes model are as follows:

	Three Months Ended				Nine Months Ended
	September 30, 2020		September 30, 2019		September 30, 2020		September 30, 2019
Dividend rate		—		—		—		—
Expected term (in years)	5.0 - 6.73		5.0 - 6.73		5.0 - 6.73		5.0 - 6.73
Risk-free interest rate	0.22 - 0.46%		1.35 - 1.79%		0.22 - 1.67%		1.35 - 2.56%
Expected volatility	36.9 - 38.2%		35 - 36%		35.8 - 38.6%		35 - 36%