Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 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
	March 31, 2019
Common stock awards granted under equity incentive plans		18,459
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		18,195
Total reserved shares of common stock		38,743

Summary of Stock-based Compensation Expense

The following table shows total stock-based compensation expense three months ended March 31, 2019 and 2018 (in thousands):

	Three Months Ended
	March 31, 2019		March 31, 2018
Cost of platform revenue	$	59	$	19
Cost of player revenue		243		44
Research and development		8,532		2,296
Sales and marketing		5,166		1,110
General and administrative		3,864		960
Total stock-based compensation	$	17,864	$	4,429

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		4			54.65		—	$	22.96
Exercised		(1,974	)		5.28		—		—
Forfeited and expired		(81	)		12.52		—		—
Balance, March 31, 2019 - outstanding		14,320		$	9.03		6.5		—	$	794,461
Options exercisable at March 31, 2019		7,749		$	4.93		5.4		—	$	461,744

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
	March 31, 2019			March 31, 2018
Dividend rate		—			—
Expected term (in years)		5.0			6.1
Risk-free interest rate	2.51 - 2.56%			2.32 - 2.67%
Expected volatility		36	%	39 - 40%

Summary of Restricted Stock Unit Activity

Pursuant to the 2017 Plan, the Company issues 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		712			50.35
Released		(165	)		45.83
Forfeited		(94	)		56.11
Balance, March 31, 2019 - outstanding		4,139		$	48.75