Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2021

Equity [Abstract]

Schedule of Reserved Shares of Common Stock for Issuance

At March 31, 2021, the Company had reserved shares of common stock for issuance as follows (in thousands):

	As of March 31, 2021
Common stock awards granted under equity incentive plans		11,457
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		27,847
Total reserved shares of common stock		44,393

* 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 three months ended March 31, 2021 is as follows (in thousands, except per share data):

	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Balance, December 31, 2020		4,355		$	92.91
Awarded		97			384.11
Released		(387	)		71.77
Forfeited		(71	)		112.86
Balance, March 31, 2021 – outstanding		3,994		$	101.66

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, 2020		8,733		$	26.19		5.7		—
Granted		10			413.11		—	$	154.43
Exercised		(1,276	)		5.25		—		—
Forfeited and expired		(4	)		7.57		—		—
Balance, March 31, 2021 - outstanding		7,463		$	30.31		5.8		—	$	2,206,030
Options exercisable at March 31, 2021		5,311		$	9.47		4.9		—	$	1,680,001

Schedule of Stock-based Compensation Expense

The following table shows total stock-based compensation expense for the three months ended March 31, 2021 and 2020 (in thousands):

	Three Months Ended
	March 31, 2021		March 31, 2020
Cost of platform revenue	$	198	$	211
Cost of player revenue		415		338
Research and development		16,554		13,255
Sales and marketing		13,363		10,057
General and administrative		10,007		6,544
Total stock-based compensation	$	40,537	$	30,405

Summary of Assumptions Used to Value Stock Options 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
	March 31, 2021		March 31, 2020
Expected term (in years)	5.0 - 6.0			5.0
Risk-free interest rate	0.36 - 0.80%		0.88 - 1.67%
Expected volatility	38.3 - 39.0%			36.0	%
Dividend rate		—		—