Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2020

Equity [Abstract]

Schedule of Reserved Shares of Common Stock for Issuance

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

	As of
	June 30, 2020
Common stock awards granted under equity incentive plans		14,365
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		22,567
Total reserved shares of common stock		42,021

* 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 six months ended June 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		586			124.63
Released		(576	)		65.27
Forfeited		(185	)		64.63
Balance, June 30, 2020 - outstanding		4,369		$	75.37

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		21			113.31		—	$	38.95
Exercised		(1,107	)		5.31		—		—
Forfeited and expired		(42	)		8.45		—		—
Balance, June 30, 2020 - outstanding		9,996		$	16.13		5.8		—	$	1,003,651
Options exercisable at June 30, 2020		6,826		$	6.66		5.0		—	$	750,064

Summary of Stock-based Compensation Expense

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

	Three Months Ended				Six Months Ended
	June 30, 2020		June 30, 2019		June 30, 2020		June 30, 2019
Cost of platform revenue	$	232	$	59	$	443	$	118
Cost of player revenue		310		246		648		489
Research and development		13,348		9,258		26,603		17,790
Sales and marketing		9,615		4,974		19,672		10,140
General and administrative		6,531		4,134		13,075		7,998
Total stock-based compensation	$	30,036	$	18,671	$	60,441	$	36,535

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					Six Months Ended
	June 30, 2020		June 30, 2019			June 30, 2020		June 30, 2019
Dividend rate		—		—			—		—
Expected term (in years)	5.0 - 5.27		5.0 - 5.27			5.0 - 5.27		5.0 - 5.27
Risk-free interest rate	0.31 - 0.37%		1.83 - 2.31%			0.31 - 1.67%		1.83 - 2.56%
Expected volatility	37.9 - 38.6%			36	%	35.8 - 38.6%			36	%