STOCKHOLDERS' EQUITY (Tables)
|
9 Months Ended |
Sep. 30, 2019 |
|---|
| Share-based Payment Arrangement [Abstract] |
|
| Summary of Stock Option Activity |
A summary of stock option activity for the nine months ended September 30, 2019 is as follows (in thousands, except share and per share data): | | | | | | | | | | | | | | | Number of Stock Options Outstanding
| | Weighted
Average
Exercise
Price | | Weighted
Average
Remaining
Contractual
Term
(in years) | | Aggregate
Intrinsic
Value | Balance at December 31, 2018 | 33,152,881 |
| | $ | 9.52 |
| | 5.45 | | $ | 1,543,793 |
| Granted | 1,184,657 |
| | 72.15 |
| | | | | Exercised | (7,881,289 | ) | | 7.97 |
| | | | | Forfeited | (136,772 | ) | | 11.70 |
| | | | | Balance at September 30, 2019 | 26,319,477 |
| | $ | 12.80 |
| | 5.23 | | $ | 1,305,789 |
| | | | | | | | | Options exercisable as of September 30, 2019 | 24,136,540 |
| | $ | 9.40 |
| | 4.92 | | $ | 1,269,509 |
|
|
| Schedule of Restricted Stock Awards and Restricted Stock Units Activity |
Activity related to RSAs and RSUs during the nine months ended September 30, 2019 is set forth below: | | | | | | | | | Number of
shares | | Weighted
Average Grant
Date Fair Value | Unvested as of December 31, 2018 | 17,934,728 |
| | $ | 31.34 |
| Granted | 5,735,224 |
| | 73.29 |
| Vested | (6,016,950 | ) | | 29.05 |
| Forfeited | (1,727,904 | ) | | 35.90 |
| Unvested as of September 30, 2019 | 15,925,098 |
| | $ | 46.82 |
|
|
| Schedule of Fair Value Assumptions for Options |
The fair value of stock options granted was estimated using the following weighted-average assumptions: | | | | | | | | Nine Months Ended September 30, | | 2019 | | 2018 | Dividend yield | — | % | | — | % | Risk-free interest rate | 2.48 | % | | 2.92 | % | Expected volatility | 39.52 | % | | 30.87 | % | Expected term (years) | 6.05 |
| | 6.19 |
|
|
| Summary of the Effect of Share-Based Compensation on the Condensed Consolidated Statements of Operations |
The following table summarizes the effects of share-based compensation on the Company's condensed consolidated statements of operations (in thousands): | | | | | | | | | | | | | | | | | | Three Months Ended September 30, | | Nine Months Ended September 30, | | 2019 | | 2018 | | 2019 | | 2018 | Cost of revenue | $ | 38 |
| | $ | 18 |
| | $ | 88 |
| | $ | 79 |
| Product development | 56,321 |
| | 39,525 |
| | 155,114 |
| | 103,813 |
| Sales and marketing | 6,269 |
| | 6,108 |
| | 20,304 |
| | 16,703 |
| General and administrative | 14,798 |
| | 13,262 |
| | 42,474 |
| | 37,261 |
| Total | $ | 77,426 |
| | $ | 58,913 |
| | $ | 217,980 |
| | $ | 157,856 |
|
|