| Summary of Stock Options Activity |
The activity for stock options under the Company’s stock plans for the years ended December 31, 2021, 2020 and 2019 is as follows:
|
|
|
|
|
|
|
|
|
|
|
|
Remaining
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
weighted-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Weighted-
|
|
|
average
|
|
|
Per share
|
|
|
|
|
|
|
|
|
|
average
|
|
|
contractual
|
|
|
average
|
|
|
|
|
|
|
|
Price per
|
|
exercise
|
|
|
terms
|
|
|
intrinsic
|
|
|
|
Options
|
|
|
share
|
|
price
|
|
|
(in years)
|
|
|
value
|
|
|
Outstanding as of December 31, 2018
|
|
1,127,336
|
|
|
$0.75-$83.30
|
|
$
|
34.89
|
|
|
|
3.84
|
|
|
$
|
89.28
|
|
|
Exercised
|
|
(109,291
|
)
|
|
0.75-58.95
|
|
|
28.45
|
|
|
|
|
|
|
|
|
|
|
Forfeited
|
|
(37,161
|
)
|
|
38.54-58.95
|
|
|
44.58
|
|
|
|
|
|
|
|
|
|
|
Outstanding as of December 31, 2019
|
|
980,884
|
|
|
0.75-83.30
|
|
|
35.24
|
|
|
|
2.84
|
|
|
|
34.07
|
|
|
Vested and exercisable as of December 31, 2019
|
|
929,825
|
|
|
0.75-83.30
|
|
|
34.73
|
|
|
|
2.81
|
|
|
|
34.64
|
|
|
Vested and expected to vest as of December 31, 2019
|
|
977,589
|
|
|
0.75-83.30
|
|
|
35.21
|
|
|
|
2.84
|
|
|
|
34.11
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Outstanding as of December 31, 2019
|
|
980,884
|
|
|
0.75-83.30
|
|
|
35.24
|
|
|
|
2.84
|
|
|
|
34.07
|
|
|
Exercised
|
|
(18,626
|
)
|
|
1.17-44.19
|
|
|
17.81
|
|
|
|
|
|
|
|
|
|
|
Forfeited
|
|
(6,779
|
)
|
|
44.19-56.72
|
|
|
48.23
|
|
|
|
|
|
|
|
|
|
|
Outstanding as of December 31, 2020
|
|
955,479
|
|
|
0.75-83.30
|
|
|
35.49
|
|
|
|
1.85
|
|
|
|
11.81
|
|
|
Vested and exercisable as of December 31, 2020
|
|
955,479
|
|
|
0.75-83.30
|
|
|
35.49
|
|
|
|
1.85
|
|
|
|
11.81
|
|
|
Vested and expected to vest as of December 31, 2020
|
|
955,479
|
|
|
0.75-83.30
|
|
|
35.49
|
|
|
|
1.85
|
|
|
|
11.81
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Outstanding as of December 31, 2020
|
|
955,479
|
|
|
0.75-83.30
|
|
|
35.49
|
|
|
|
1.85
|
|
|
|
11.81
|
|
|
Exercised
|
|
(486,038
|
)
|
|
0.75-46.66
|
|
|
28.19
|
|
|
|
|
|
|
|
|
|
|
Forfeited
|
|
(10,000
|
)
|
|
83.30
|
|
|
83.30
|
|
|
|
|
|
|
|
|
|
|
Outstanding as of December 31, 2021
|
|
459,441
|
|
|
1.17-83.30
|
|
|
42.18
|
|
|
|
1.36
|
|
|
|
4.31
|
|
|
Vested and exercisable as of December 31, 2021
|
|
459,441
|
|
|
1.17-83.30
|
|
|
42.18
|
|
|
|
1.36
|
|
|
|
4.31
|
|
|
Vested and expected to vest as of December 31, 2021
|
|
459,441
|
|
|
$1.17-$83.30
|
|
$
|
42.18
|
|
|
|
1.36
|
|
|
$
|
4.31
|
|
|
| Summary of Restricted Stock Activity |
Stock Awards activity for the years ended December 31, 2021, 2020 and 2019 is summarized below:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Weighted-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
average
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
grant
|
|
|
|
|
|
|
|
Performance
|
|
|
|
|
|
|
date fair
|
|
|
|
|
|
|
|
and
|
|
|
|
|
|
|
value
|
|
|
Restricted stock units
|
Time-based
|
|
|
time-based
|
|
|
Total
|
|
|
per share
|
|
|
Unvested restricted stock units as of December 31, 2018 (1)
|
|
58,589
|
|
|
$
|
8,739
|
|
|
|
67,328
|
|
|
$
|
115.16
|
|
|
Granted
|
|
87,902
|
|
|
|
—
|
|
|
|
87,902
|
|
|
|
75.56
|
|
|
Vested
|
|
(24,680
|
)
|
|
|
(4,366
|
)
|
|
|
(29,046
|
)
|
|
|
123.53
|
|
|
Forfeited/canceled
|
|
(12,835
|
)
|
|
|
(1,239
|
)
|
|
|
(14,074
|
)
|
|
|
102.89
|
|
|
Unvested restricted stock units as of December 31, 2019 (1)
|
|
108,976
|
|
|
|
3,134
|
|
|
|
112,110
|
|
|
$
|
83.48
|
|
|
Unvested and expected to vest restricted stock units outstanding as of
December 31, 2019
|
|
|
|
|
|
|
|
|
|
103,087
|
|
|
$
|
83.22
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Unvested restricted stock units as of December 31, 2019
|
|
108,976
|
|
|
|
3,134
|
|
|
|
112,110
|
|
|
$
|
83.48
|
|
|
Granted
|
|
210,622
|
|
|
|
88,458
|
|
|
|
299,080
|
|
|
|
43.52
|
|
|
Vested
|
|
(49,636
|
)
|
|
|
—
|
|
|
|
(49,636
|
)
|
|
|
83.31
|
|
|
Forfeited/canceled
|
|
(24,500
|
)
|
|
|
(3,134
|
)
|
|
|
(27,634
|
)
|
|
|
70.60
|
|
|
Unvested restricted stock units as of December 31, 2020 (1)
|
|
245,462
|
|
|
|
88,458
|
|
|
|
333,920
|
|
|
$
|
49.29
|
|
|
Unvested and expected to vest restricted stock units outstanding as of
December 31, 2020
|
|
|
|
|
|
|
|
|
|
246,420
|
|
|
$
|
49.82
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Unvested restricted stock units as of December 31, 2020
|
|
245,462
|
|
|
|
88,458
|
|
|
|
333,920
|
|
|
$
|
49.29
|
|
|
Granted
|
|
240,044
|
|
|
|
88,902
|
|
|
|
328,946
|
|
|
|
56.01
|
|
|
Vested
|
|
(109,504
|
)
|
|
|
—
|
|
|
|
(109,504
|
)
|
|
|
52.79
|
|
|
Forfeited/canceled
|
|
(86,836
|
)
|
|
|
(78,248
|
)
|
|
|
(165,084
|
)
|
|
|
46.88
|
|
|
Unvested restricted stock units as of December 31, 2021 (1)
|
|
289,166
|
|
|
|
99,112
|
|
|
|
388,278
|
|
|
$
|
54.81
|
|
|
Unvested and expected to vest restricted stock units outstanding as of
December 31, 2021
|
|
|
|
|
|
|
|
|
|
331,358
|
|
|
$
|
54.98
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Weighted-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
average
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
grant
|
|
|
|
|
|
|
|
Performance
|
|
|
|
|
|
|
date fair
|
|
|
|
|
|
|
|
and
|
|
|
|
|
|
|
value
|
|
|
Restricted stock awards
|
Time-based
|
|
|
time-based
|
|
|
Total
|
|
|
per share
|
|
|
Unvested restricted stock awards outstanding as of December 31, 2018 (1)
|
|
36,937
|
|
|
|
47,821
|
|
|
|
84,758
|
|
|
$
|
115.80
|
|
|
Granted
|
|
54,853
|
|
|
|
40,166
|
|
|
|
95,019
|
|
|
|
86.10
|
|
|
Vested
|
|
(13,627
|
)
|
|
|
(15,732
|
)
|
|
|
(29,359
|
)
|
|
|
115.37
|
|
|
Forfeited/canceled
|
|
(7,093
|
)
|
|
|
(9,627
|
)
|
|
|
(16,720
|
)
|
|
|
109.11
|
|
|
Unvested restricted stock awards outstanding as of December 31, 2019 (1)
|
|
71,070
|
|
|
|
62,628
|
|
|
|
133,698
|
|
|
$
|
95.74
|
|
|
Unvested and expected to vest restricted stock awards outstanding as of
December 31, 2019
|
|
|
|
|
|
|
|
|
|
79,473
|
|
|
$
|
90.31
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Unvested restricted stock awards outstanding as of December 31, 2019
|
|
71,070
|
|
|
|
62,628
|
|
|
|
133,698
|
|
|
$
|
95.74
|
|
|
Vested
|
|
(28,994
|
)
|
|
|
—
|
|
|
|
(28,994
|
)
|
|
|
89.37
|
|
|
Forfeited/canceled
|
|
—
|
|
|
|
(29,273
|
)
|
|
|
(29,273
|
)
|
|
|
110.27
|
|
|
Unvested restricted stock awards outstanding as of December 31, 2020 (1)
|
|
42,076
|
|
|
|
33,355
|
|
|
|
75,431
|
|
|
$
|
93.96
|
|
|
Unvested and expected to vest restricted stock awards outstanding as of
December 31, 2020
|
|
|
|
|
|
|
|
|
|
44,159
|
|
|
$
|
85.90
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Unvested restricted stock awards outstanding as of December 31, 2020
|
|
42,076
|
|
|
|
33,355
|
|
|
|
75,431
|
|
|
$
|
93.96
|
|
|
Vested
|
|
(15,728
|
)
|
|
|
—
|
|
|
|
(15,728
|
)
|
|
|
91.17
|
|
|
Forfeited/canceled
|
|
(15,932
|
)
|
|
|
(27,726
|
)
|
|
|
(43,658
|
)
|
|
|
98.05
|
|
|
Unvested restricted stock awards outstanding as of December 31, 2021 (1)
|
|
10,416
|
|
|
|
5,629
|
|
|
|
16,045
|
|
|
$
|
87.12
|
|
|
Unvested and expected to vest restricted stock awards outstanding as of
December 31, 2021
|
|
|
|
|
|
|
|
|
|
15,532
|
|
|
$
|
90.08
|
|
|
(1)
|
Outstanding restricted stock units and restricted stock awards are based on the maximum payout of the targeted number of shares.
|
|
| Summary of Stock-based Compensation Expense |
Stock-based compensation
Stock-based compensation expense recognized for the years ended December 31, 2021, 2020 and 2019, was as follows:
|
(amounts in thousands)
|
Years ended December 31,
|
|
|
Stock-based compensation expense by type of award:
|
2021
|
|
|
2020
|
|
|
2019
|
|
|
Stock option plan awards
|
$
|
—
|
|
|
$
|
709
|
|
|
$
|
2,977
|
|
|
Restricted stock units and restricted stock awards
|
|
10,229
|
|
|
|
6,717
|
|
|
|
5,413
|
|
|
Employee stock purchase plan
|
|
714
|
|
|
|
777
|
|
|
|
739
|
|
|
Total stock-based compensation expense
|
$
|
10,943
|
|
|
$
|
8,203
|
|
|
$
|
9,129
|
|
For the years ended December 31, 2021, 2020 and 2019, respectively, stock-based compensation expense recognized under ASC 718, included in cost of revenue, research and development expense, sales and marketing expense, and general and administrative expense was as follows:
|
|
Years ended December 31,
|
|
|
(amounts in thousands)
|
2021
|
|
|
2020
|
|
|
2019
|
|
|
Cost of revenue
|
$
|
1,106
|
|
|
$
|
698
|
|
|
$
|
890
|
|
|
Research and development
|
|
1,276
|
|
|
|
969
|
|
|
|
1,100
|
|
|
Sales and marketing
|
|
2,388
|
|
|
|
2,208
|
|
|
|
1,755
|
|
|
General and administrative
|
|
6,173
|
|
|
|
4,328
|
|
|
|
5,384
|
|
|
Total stock-based compensation expense
|
$
|
10,943
|
|
|
$
|
8,203
|
|
|
$
|
9,129
|
|
|