Stockholders' Equity
The Company's authorized capital stock consists of 310,000,000 shares, all with a par value of $0.0001 per share, of which 300,000,000 shares are designated as common stock and 10,000,000 shares are designated as preferred stock. There were no shares of preferred stock outstanding as of December 31, 2025 and 2024.
Equity Offerings
In October 2023, the Company completed a public sale of its common stock, receiving aggregate net proceeds of $95.8 million. In addition to the sale of common stock, the Company issued prefunded warrants to purchase 7,500,000 shares of the Company's common stock at $2.4999 per underlying share of common stock. The exercise price of the warrants is $0.0001 per underlying share of common stock, were fully exercisable upon issuance, and have no expiration date. In October 2025, certain prefunded warrants were exercised, resulting in the issuance of 2,285,000 shares. As of December 31, 2025, prefunded warrants to purchase 5,215,000 shares of the Company's common stock remained outstanding.
In February 2024, the Company completed a public sale of its common stock, receiving aggregate net proceeds of $161.7 million.
At-the-Market (ATM) Offerings
On May 6, 2021, the Company entered into a sales agreement (Sales Agreement) with Cowen and Company, LLC (Cowen), under which the Company may from time to time issue and sell shares of its common stock through ATM offerings for an aggregate offering price of up to $100.0 million. Cowen will act as the Company's sales agent for the ATM program and is entitled to compensation for its services up to 3% of the gross proceeds of any shares of common stock sold under the Sales Agreement. In December 2023, the Company sold 1,250,000 shares under the ATM for $2.60 per share and received $3.1 million in net proceeds.
In January 2024, the Company amended and restated its Sales Agreement with Cowen to reset the ATM program and provide for the offer and sale of shares of common stock having an aggregate gross offering price of up to $100.0 million. All other terms of the amended and restated Sales Agreement are substantially the same as the original Sales Agreement. The Company has not yet issued or sold any common stock under the amended and restated Sales Agreement.
Equity Incentive Plans
In January 2020, the Company’s board of directors approved the 2020 Equity Incentive Plan (2020 Plan), which became effective January 30, 2020 in connection with the IPO. The 2020 Plan serves as the successor incentive award plan to the Company’s 2017 Equity Incentive Plan (2017 Plan) and initially reserved 2,134,000 shares of common stock available for issuance pursuant to a variety of stock-based compensation awards, including stock options, stock appreciation rights, restricted stock awards, restricted stock unit (RSU) awards, and other stock-based awards, plus 1,550,150 shares of common stock that were reserved for issuance pursuant to future awards under the 2017 Plan at the time the 2020 Plan became effective, plus shares represented by awards outstanding under the 2017 Plan that are forfeited or lapsed unexercised and which following the effective date of the 2020 Plan are not issued under the 2017 Plan. In addition, the 2020 Plan reserve will increase on January 1 of each year beginning in 2021 through 2030, by an amount equal to the lesser of (a) 4% of the shares of stock outstanding (on an as converted basis) on the day immediately prior to the date of increase and (b) such smaller number of shares of stock as determined by the Company's board of directors; provided, however, that no more than 11,000,000 shares of stock may be issued upon the exercise of incentive stock options. Accordingly, on January 1, 2026, 2025 and 2024, the 2020 Plan reserve increased by 4,933,306, 4,713,921, and 3,871,494 shares, respectively. As of December 31, 2025, the Company had 4,093,603 shares available for future grant under the 2020 Plan.
The 2020 Plan provides for the Company to sell or issue common stock or restricted common stock, or to grant incentive stock options or nonqualified stock options for the purchase of common stock, to employees, members of the board of directors, and consultants of the Company under terms and provisions established by the board of directors. Under the terms of the 2020 Plan, options may be granted at an exercise price not less than fair market value. The Company generally grants stock-based awards with service conditions. Options granted typically vest over a four-year period but may be granted with different vesting terms.
Following the Company’s IPO and in connection with the effectiveness of the Company’s 2020 Plan, the 2017 Plan terminated and no further awards will be granted under that plan. However, all outstanding awards under the 2017 Plan will continue to be governed by their existing terms.
In December 2021, the Company’s board of directors approved the 2022 Employment Inducement Incentive Plan (2022 Plan). The 2022 Plan initially reserved 1,250,000 shares of common stock available for issuance pursuant to a variety of stock-based compensation awards, including stock options, stock appreciation rights, restricted stock awards, RSU awards, and other stock-based awards. In November 2022, the 2022 Plan reserve was increased by 1,500,000. As of December 31, 2025, the Company had 111,533 shares available for future grant under the 2022 Plan.
Stock Option Exchange Program
On January 16, 2024, the Company commenced an offer to certain eligible employees and consultants to exchange certain outstanding eligible options to purchase shares of the Company’s common stock for a lesser number of restricted stock unit (RSU) awards pursuant to an option exchange program (the Option Exchange). The Option Exchange expired on February 12, 2024. Pursuant to the Option Exchange, eligible option holders elected to exchange, and the Company accepted for cancellation, eligible options to purchase an aggregate of 5,059,129 shares of the Company’s common stock, representing approximately 98% of the total shares of common stock underlying the eligible options. On February 13, 2024, immediately following the expiration of the Option Exchange, the Company granted 2,129,594 shares of Replacement RSU Awards, pursuant to the terms of the Option Exchange. The Replacement RSU Awards will vest based on continued service with the Company over a period of either 1, 2 or 3 years, depending on the grant date of the exchanged options.
The exchange of stock options was treated as a modification for accounting purposes, which requires an incremental expense of $8.6 million to be recognized for the Replacement RSU Awards over their new service periods (1 - 3 years). In addition, any unamortized expense remaining on the exchanged options as of the modification will be recognized over their original remaining service period.
Stock Option Activity
The following summarizes option activity:
Number of
Options
Weighted-
Average
Exercise
Price
Remaining
Contractual
Term
(Years)
Aggregate
Intrinsic
Value ($ in thousands)
Balance—December 31, 20245,342,909 $6.69 8.01$43,120 
Granted2,345,398 14.10 
Exercised(714,125)6.44 
Forfeited(534,345)9.55 
Expired(2,865)26.87 
Balance—December 31, 20256,436,972 $9.17 7.75$127,945 
Exercisable—December 31, 2025
2,903,391 $8.46 6.63$59,750 
The aggregate intrinsic value is calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock as of December 31, 2025. The intrinsic value of options exercised for the years ended December 31, 2025, 2024, and 2023 were $10.0 million, $4.2 million and $1.2 million, respectively.
The total grant-date fair value of the options vested during the years ended December 31, 2025, 2024, and 2023 were $8.5 million, $4.0 million and $28.0 million, respectively. The weighted-average grant-date fair value of options granted during the years ended December 31, 2025, 2024, and 2023 were $9.94, $3.70 and $8.01, respectively.
Restricted Stock Unit Activity
The following table summarizes information regarding the Company's RSUs:
Number of UnitsWeighted-Average
Grant Date Fair Value
Balance—December 31, 20246,055,087 $8.04 
Granted3,063,418 14.23 
Vested(2,275,607)8.24 
Forfeited(835,383)10.12 
Unvested Balance—December 31, 20256,007,515 $10.83 
The grant date fair value of an RSU equals the closing price of the Company's common stock on the grant date. The total grant-date fair value of the RSUs vested during the years ended December 31, 2025, 2024, and 2023 were $18.8 million, $17.4 million, and $9.3 million, respectively. RSUs generally vest equally over four years, except for those issued in connection with the Option Exchange, as previously described.
Stock-Based Compensation Expense
Stock-based compensation expense included in the consolidated statements of operations and comprehensive loss was as follows (in thousands):
Year Ended December 31,
202520242023
Research and development
$12,336 $13,509 $15,544 
Selling, general and administrative28,028 28,221 23,269 
Total stock-based compensation expense
$40,364 $41,730 $38,813 
As of December 31, 2025, there was $25.7 million of total unrecognized compensation cost related to unvested options that are expected to vest, which is expected to be recognized over a weighted-average period of 2.6 years. As of December 31, 2025, there was $47.5 million of total unrecognized compensation cost related to RSUs that are expected to vest, which is expected to be recognized over a weighted-average period of 2.8 years.
In determining the fair value of the stock options granted, the Company uses the Black-Scholes option-pricing model and assumptions discussed below. Each of these inputs is subjective and generally requires significant judgment.
Fair value of common stock—The Company uses its closing stock price as reported on Nasdaq on the grant date for the fair value of its stock.
Expected Term—The Company’s expected term represents the period that the Company’s stock-based awards are expected to be outstanding. The Company uses the simplified method (based on the mid-point between the vesting date and the end of the contractual term) to determine the expected term as it does not have sufficient prior exercise data to calculate based on historical data.
Expected Volatility— The Company uses its own historical stock price for expected volatility.
Risk-Free Interest Rate—The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of option.
Dividend Yield—The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero.
The fair value of stock option awards granted was estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions:
Year Ended December 31,
202520242023
Expected term (in years)
5.3 – 6.1
1.8 – 6.1
5.0 – 6.1
Expected volatility
72.9 – 79.5%
79.1 – 83.2%
75.2% – 78.4%
Risk-free interest rate
3.7 – 4.4%
3.6 – 5.0%
3.5 – 4.7%
Dividend yield
—%—%—%
2020 Employee Stock Purchase Plan
The Company adopted the 2020 Employee Stock Purchase Plan, or the ESPP, which became effective on January 30, 2020 in connection with the IPO. The ESPP is designed to allow the Company’s eligible employees to purchase shares of the Company’s common stock, at semi-annual intervals, with their accumulated payroll deductions. Under the ESPP, participants are offered the option to purchase shares of the Company’s common stock at a discount during a series of successive offering periods. The option purchase price will be the lower of 85% of the closing trading price per share of the Company’s common stock on the first trading date of an offering period in which a participant is enrolled or 85% of the closing trading price per share on the purchase date, which will occur on the last trading day of each offering period.
The ESPP is intended to qualify under Section 423 of the U.S. Internal Revenue Service Code of 1986, as amended. The maximum number of the Company’s common stock which will be authorized for sale under the ESPP is equal to the sum of (a) 351,000 shares of common stock and (b) an annual increase on the first day of each year beginning in 2021 and ending in 2030, equal to the lesser of (i) 1% of the shares of common stock outstanding (on an as converted basis) on the last day of the immediately preceding fiscal year and (ii) such number of shares of common stock as determined by the Company’s board of directors; provided, however, no more than 5,265,000 shares of the Company’s common stock may be issued under the ESPP. Accordingly, on January 1, 2026, 2025 and 2024, the ESPP reserve increased by 1,216,890, 1,178,480, and 967,873 shares, respectively. As of December 31, 2025, the Company had 2,806,818 shares available for future grant under the ESPP.
Stock-based compensation expense related to the ESPP was $1.0 million, $0.9 million, and $0.9 million for the years ended December 31, 2025, 2024 and 2023, respectively.

Historical Timeline

Fiscal YearFiled
2025Feb 25, 2026Showing above
2024Feb 25, 2025
2023Feb 27, 2024

About Stock Compensation Disclosures

Stock-based compensation disclosures detail the equity awards granted to employees and executives — including stock options, restricted stock units (RSUs), and performance shares — along with the valuation methods and assumptions used to expense them. This section reveals the true cost of talent retention and the alignment between management incentives and shareholder interests.

Key signals: total unrecognized compensation expense and its expected recognition period signal future earnings headwinds from already-granted awards. For stock options, examine Black-Scholes assumptions — expected volatility, risk-free rate, and expected term — as understating any of these reduces reported compensation expense. Compare stock compensation expense as a percentage of revenue against peers to assess dilution cost. Watch vesting schedules for acceleration clauses tied to change-of-control events. Performance-based awards with undemanding targets may indicate weak governance. Add back stock compensation to operating cash flow to calculate a more conservative free cash flow figure.