Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Tables)

v3.20.4
Stock-Based Compensation (Tables)
12 Months Ended
Dec. 31, 2020
Share-based Payment Arrangement [Abstract]  
Summary of stock option activity
The following table summarizes the activity for all stock options under all of the Company’s equity incentive plans for the years ended December 31, 2020 and 2019 (shares and aggregate intrinsic value in thousands):
Number of Options
Weighted
Average
Exercise Price
Weighted
Average
Remaining
Contractual Life
Aggregate
Intrinsic
Value
Outstanding at December 31, 2018 13,590  $ 6.07  6.63 $ 66,462 
Granted
1,362  15.44 
Exercised
(3,625) 5.48 
Cancelled (543) 7.62 
Outstanding at December 31, 2019 10,784  7.38  6.52 71,745 
Assumed through acquisition 2,565  10.23 
Granted
1,740  17.48 
Exercised
(6,608) 7.40 
Cancelled (462) 9.36 
Outstanding at December 31, 2020 8,019  $ 10.35  6.87 $ 473,371 
Options vested and exercisable at December 31, 2020 4,277  $ 6.65  5.35 $ 268,284 
Options vested and expected to vest at December 31, 2020 8,019  $ 10.35  6.87 $ 473,371 
Estimated fair value of stock options
The Company estimated the fair value of stock options with the following assumptions:
Year Ended December 31,
2020 2019 2018
Risk-free interest rate
0.30% - 1.50%
1.70% - 2.59%
 2.72% - 2.92%
Volatility
54.40% - 59.70%
52.90% - 55.07%
44.87% - 54.61%
Expected term (in years)
5.30 - 6.10
6.10 - 6.12
6.09 - 6.11
Expected dividend yield
0.00%
0.00%
0.00%
Summary of activity for all RSUs
The following table summarizes the activity for all RSUs under all of the Company’s equity incentive plans for the years ended December 31, 2020 and 2019 (shares in thousands):
Shares
Weighted
Average Grant
Date Fair
Value
Unvested balance at December 31, 2018 4,182  $ 7.05 
Granted
2,258  15.25 
Issued
(1,104) 6.83 
Cancelled / forfeited
(1,393) 8.14 
Unvested balance at December 31, 2019 3,943  11.42 
Assumed through acquisition 3,033  70.54 
Granted
5,295  34.71 
Issued
(4,222) 30.10 
Cancelled / forfeited
(946) 32.08 
Unvested balance at December 31, 2020 7,103  $ 40.17 
Summary of stock-based compensation expense
The Company recognized stock-based compensation expense, including ESPP expenses, in the consolidated statements of operations as follows (in thousands): 
Year Ended December 31,
2020 2019 2018
Cost of customer agreements and incentives $ 4,315  $ 2,434  $ 2,568 
Cost of solar energy systems and product sales
1,582  844  718 
Sales and marketing
53,366  5,162  7,191 
Research and development
2,518  1,439  1,253 
General and administration
108,806  16,427  16,126 
Total
$ 170,587  $ 26,306  $ 27,856