Equity Incentive Plans (Tables)
|
12 Months Ended |
Dec. 31, 2023 |
Nonvested Restricted Stock Shares Activity |
RSU activity for the years ended December 31, 2023 and 2022 was as follows:
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Shares |
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|
Weighted- Average Grant-Date Fair Value |
|
Unvested at December 31, 2021 |
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|
— |
|
|
$ |
— |
|
Granted |
|
|
581,047 |
|
|
|
26.25 |
|
Vested and released |
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|
(79,229 |
) |
|
|
24.79 |
|
Cancelled |
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|
(45,052 |
) |
|
|
24.32 |
|
Unvested at December 31, 2022 |
|
|
456,766 |
|
|
$ |
26.70 |
|
Granted |
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|
574,123 |
|
|
|
45.57 |
|
Vested and released |
|
|
(232,890 |
) |
|
|
30.97 |
|
Cancelled |
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|
(44,537 |
) |
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|
40.78 |
|
Unvested at December 31, 2023 |
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|
753,462 |
|
|
$ |
38.93 |
|
|
Summary of Activity under Employee Stock Purchase Plan |
Activity under our 2020 ESPP was as follows:
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Shares |
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Balance - December 31, 2021 |
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1,070,704 |
|
Additional shares authorized |
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|
530,319 |
|
Shares purchased |
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|
(61,709 |
) |
Balance - December 31, 2022 |
|
|
1,539,314 |
|
Additional shares authorized |
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|
794,706 |
|
Shares purchased |
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|
(76,275 |
) |
Balance - December 31, 2023 |
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|
2,257,745 |
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|
Summary of Estimated Fair Value of Employee Stock Options |
We estimated the fair value of employee stock options using the Black-Scholes option-pricing model for the years ended December 31, 2023, 2022 and 2021 using the following weighted-average assumptions:
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Year Ended December 31, |
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2023 |
|
2022 |
|
2021 |
Fair Value Assumptions |
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|
Expected volatility |
|
71.3% - 74.0% |
|
78.1% - 85.1% |
|
81.0% - 84.1% |
Expected dividend yield |
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0% |
|
0% |
|
0% |
Expected term (in years) |
|
5.3 - 5.4 |
|
5.3 - 5.5 |
|
5.3 - 5.5 |
Risk-free interest rate |
|
3.5% - 4.6% |
|
1.6% - 4.4% |
|
0.5% - 1.3% |
|
2020 Plan and 2014 Plan |
|
Summary of Activity Under Stock Option Plans |
Stock option activity under our 2020 Plan and 2014 Plan, which excludes options to purchase 36,710 shares granted outside of the 2020 Plan and 2014 Plan, was as follows:
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Options Outstanding |
|
Stock Option and Restricted Stock Units Activity |
|
Options and RSUs Available for Grant |
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|
Number of Options |
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|
Weighted- Average Exercise Price Per Share |
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Weighted- Average Remaining Contractual Term (Years) |
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Aggregate Intrinsic Value |
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Balances — December 31, 2021 |
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|
6,104,756 |
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|
5,295,007 |
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|
$ |
9.30 |
|
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|
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|
Additional shares authorized |
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|
2,651,598 |
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|
— |
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Options granted |
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(3,850,981 |
) |
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|
3,850,981 |
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|
$ |
27.67 |
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|
Options exercised |
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|
385 |
|
(1) |
|
(1,153,285 |
) |
|
$ |
4.25 |
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|
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|
Options forfeited |
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|
277,209 |
|
|
|
(277,209 |
) |
|
$ |
23.54 |
|
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|
|
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|
|
Restricted Stock Units granted |
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|
(581,047 |
) |
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|
|
|
|
|
|
|
|
|
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|
Restricted Stock Units withheld |
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|
32,626 |
|
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Restricted Stock Units forfeited |
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|
45,052 |
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Balances — December 31, 2022 |
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|
4,679,598 |
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|
7,715,494 |
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|
$ |
18.70 |
|
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|
8.20 |
|
|
$ |
225,667 |
|
Additional shares authorized |
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|
3,973,533 |
|
|
|
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Options granted |
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|
(2,343,037 |
) |
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|
2,343,037 |
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|
$ |
44.44 |
|
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|
Options exercised |
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|
1,080 |
|
(1) |
|
(538,888 |
) |
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$ |
10.50 |
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|
Options forfeited |
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|
204,807 |
|
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|
(204,807 |
) |
|
$ |
32.58 |
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|
Restricted Stock Units granted |
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|
(574,123 |
) |
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|
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|
Restricted Stock Units withheld |
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|
78,755 |
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Restricted Stock Units forfeited |
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|
44,537 |
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Balances — December 31, 2023 |
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|
6,065,150 |
|
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|
9,314,836 |
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|
$ |
25.35 |
|
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|
7.75 |
|
|
$ |
348,868 |
|
Vested and expected to vest — December 31, 2023 |
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|
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|
9,314,836 |
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|
$ |
25.35 |
|
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|
7.75 |
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|
$ |
348,868 |
|
Exercisable at December 31, 2023 |
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|
4,646,989 |
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|
$ |
16.40 |
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|
6.80 |
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|
$ |
215,608 |
|
______________________________________ (1)Shares returned due to net exercises.
|
2020 Employee Stock Purchase Plan |
|
Summary of Estimated Fair Value of Shares Under Employee Stock Purchase Plan |
We estimated the fair value of shares under the 2020 ESPP using the Black-Scholes option-pricing model for the years ended December 31, 2023, 2022 and 2021 using the following weighted-average assumptions:
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|
Year Ended December 31, |
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|
2023 |
|
2022 |
|
2021 |
Fair Value Assumptions |
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|
|
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|
Expected volatility |
|
38.1% - 99.7% |
|
78.8% - 99.7% |
|
79.6% - 126.3% |
Expected dividend yield |
|
0% |
|
0% |
|
0% |
Expected term (in years) |
|
0.5 - 2.0 |
|
0.5 - 2.0 |
|
0.5 - 2.0 |
Risk-free interest rate |
|
4.2% - 5.4% |
|
0.1% - 4.7% |
|
0.0% - 0.5% |
|
2014 Plan, 2020 Plan and 2020 ESPP |
|
Summary of Stock-based Compensation Expense |
We recorded total stock-based compensation expense for the years ended December 31, 2023, 2022 and 2021 related to the 2014 Plan, the 2020 Plan and the 2020 ESPP in the consolidated statements of operations and allocated the amounts as follows:
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Year Ended December 31, |
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2023 |
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2022 |
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|
2021 |
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|
(In thousands) |
|
Research and development |
|
$ |
23,275 |
|
|
$ |
9,899 |
|
|
$ |
3,954 |
|
General and administrative |
|
|
25,485 |
|
|
|
13,751 |
|
|
|
6,775 |
|
Total |
|
$ |
48,760 |
|
|
$ |
23,650 |
|
|
$ |
10,729 |
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|