XML 47 R31.htm IDEA: XBRL DOCUMENT v3.20.4
Share-Based Compensation (Tables)
12 Months Ended
Dec. 31, 2020
Share-based Payment Arrangement [Abstract]  
Summary of shares available for grant
The following table summarizes the shares available for grant under the 2018 Plan:
Shares Available for Grant
Balance - December 31, 20193,297,638 
Authorized2,144,521 
Granted(512,945)
Shares withheld to cover taxes16,742 
Forfeited75,314 
Balance - December 31, 20205,021,270 
Schedule of fair value assumptions
Following are the assumptions used in the Black-Scholes valuation model for options granted during the periods shown below:
Year Ended December 31,
202020192018
Risk-free interest rate1.3%2.3%2.8%
Average expected term (years)7.06.15.8
Expected volatility55.0%55.0%55.0%
Dividend yield
Schedule of stock option activity
The following table summarizes the Company’s stock option activity during the period from December 31, 2017 through December 31, 2020:
Number
of
Stock
Options
Weighted
Average
Exercise
Price
Weighted
Average
Remaining
Contractual
Life (Years)
Aggregate
Intrinsic
Value (in thousands)(1)
Outstanding at December 31, 20174,207,029 $0.88 7.2$8,936 
Granted2,136,012 $6.49 $— 
Exercised(1,139,962)$1.20 $5,722 
Cancelled/Forfeited(82,786)$2.03 $— 
Outstanding at December 31, 2018
5,120,293 $3.13 7.3$81,371 
Granted1,571,925 $39.01 $— 
Exercised(1,429,756)$1.87 $121,591 
Cancelled/Forfeited(91,486)$9.33 $— 
Outstanding at December 31, 20195,170,976 $14.28 7.5$329,879 
Granted268,193 $99.74 $— 
Exercised(1,163,374)$7.75 $132,935 
Cancelled/Forfeited(57,517)$37.14 $— 
Outstanding at December 31, 20204,218,278 $21.20 6.6$443,595 
Vested and exercisable at December 31, 20202,634,631 $9.74 5.7$305,890 
Vested and expected to vest at December 31, 20203,869,597 $18.26 6.5$417,857 
__________
(1) Aggregate intrinsic value is calculated as the difference between the value of common stock on the transaction date and the exercise price multiplied by the number of shares issuable under the stock option. Aggregate intrinsic value of shares outstanding at the beginning and end of the reporting period is calculated as the difference between the value of common stock on the beginning and end dates, respectively, and the exercise price multiplied by the number of shares outstanding.
Schedule of RSU activity
The following table summarizes the Company’s RSU activity from January 1, 2019 through December 31, 2020:
Number of UnitsWeighted
Average
Grant Date Fair Value Per Unit
Unvested at January 1, 2019
— $— 
Granted173,196 $126.29 
Vested(23,552)$84.84 
Cancelled/Forfeited(640)$— 
Unvested at December 31, 2019149,004 $132.73 
Granted244,752 $109.61 
Vested(99,970)$127.71 
Cancelled/Forfeited(17,797)$— 
Unvested at December 31, 2020275,989 $114.99 
Schedule of restricted stock activity
The following table summarizes the Company’s restricted stock activity:
Number
of Shares of
Restricted Stock
Weighted
Average
Remaining
Contractual
Life (Years)
Weighted
Average
Grant Date
Fair Value
Per Share
Unvested at December 31, 2017— $— 
Granted135,791 $17.03 
Vested/Released(35,664)$17.03 
Cancelled/Forfeited— $— 
Unvested at December 31, 2018100,127 1.6$17.03 
Granted99,433 $20.02 
Vested/Released(87,239)$19.21 
Cancelled/Forfeited(23,333)$— 
Unvested at December 31, 201988,988 1.2$19.49 
Granted— $— 
Vested/Released(76,804)$19.97 
Cancelled/Forfeited— $— 
Unvested at December 31, 202012,184 0.3$20.02