Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2019

Equity [Abstract]

Schedule of Reserved Shares of Common Stock for Future Issuances

The Company has reserved the following shares of common stock for future issuances (in thousands):

	As of
	June 30, 2019
Common stock awards granted under equity incentive plans		16,595
Common stock awards available for issuance under Employee Stock Purchase Plan		2,089
Common stock awards available for issuance under the 2017 Equity Incentive Plan		18,190
Total reserved shares of common stock		36,874

Summary of Stock-based Compensation Expense

The following table shows total stock-based compensation expense for the three and six months ended June 30, 2019 and 2018 (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2019		June 30, 2018		June 30, 2019		June 30, 2018
Cost of platform revenue	$	59	$	19	$	118	$	38
Cost of player revenue		246		67		489		111
Research and development		9,258		2,801		17,790		5,097
Sales and marketing		4,974		1,286		10,140		2,396
General and administrative		4,134		1,136		7,998		2,096
Total stock-based compensation	$	18,671	$	5,309	$	36,535	$	9,738

Schedule of Stock Option Activity

The summary of the Company’s stock option activity is as follows (in thousands, except price 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, 2018 - outstanding		16,371		$	8.59				—
Granted		26			80.25		—	$	28.95
Exercised		(3,625	)		5.37		—		—
Forfeited and expired		(339	)		8.39		—		—
Balance, June 30, 2019 - outstanding		12,433		$	9.68		6.5		—	$	1,005,879
Options exercisable at June 30, 2019		6,860		$	5.12		5.2		—	$	586,269

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, 2019			June 30, 2018		June 30, 2019			June 30, 2018
Dividend rate		—			—		—			—
Expected term (in years)	5.0 - 5.27			5.3 - 6.1		5.0 - 5.27			5.3 - 6.1
Risk-free interest rate	1.83 - 2.31%			2.61 - 2.88%		1.83 - 2.56%			2.32 - 2.88%
Expected volatility		36	%	38 - 39%			36	%	38 - 40%

Summary of Restricted Stock Unit Activity

Pursuant to the 2017 Plan, the Company grants restricted stock units to employees. The fair value of restricted stock units is based on the Company’s closing stock price on the date of grant. The summary of the Company’s restricted stock unit activity is as follows (in thousands, except price per share data):

	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Balance, December 31, 2018 - outstanding		3,686		$	48.50
Awarded		1,081			57.36
Released		(381	)		46.16
Forfeited		(224	)		53.46
Balance, June 30, 2019 - outstanding		4,162		$	50.75