IonQ, Inc. Stock Compensation Disclosure

16. STOCK-BASED COMPENSATION

Equity Incentive Plans

The Company sponsors the 2015 Equity Incentive Plan (the “2015 Plan”), which provided for the grant of share-based compensation to certain officers, directors, employees, consultants, and advisors. Subsequent to September 2021, no further awards were made pursuant to the 2015 Plan. For awards granted under the 2015 Plan, vesting generally occurs over four to five years from the date of grant.

The Company also sponsors the 2021 Equity Incentive Plan (the “2021 Plan”), which provides for the grant of stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards (“RSU”), performance awards and other forms of awards to employees, directors, and consultants. The number of shares of the Company’s common stock reserved for issuance under the 2021 Plan automatically increases on January 1 of each year, through and including January 1, 2031, by 5% of the fully diluted common stock (as defined in the 2021 Plan) outstanding on December 31 of the preceding year, or a lesser number of shares determined by the Company’s board of directors prior to such increase. As of January 1, 2026, the number of shares reserved for issuance under the 2021 Plan increased by 25,069,103. For awards granted under the 2021 Plan, vesting terms range from less than one year to four years from the date of grant.

In May 2025, in connection with the Lightsynq Acquisition, the Company assumed the Lightsynq Technologies Inc. 2024 Equity Incentive Plan (the “Lightsynq Plan”). Upon closing of the Lightsynq Acquisition, no further awards were made pursuant to

the Lightsynq Plan and certain outstanding Lightsynq stock options under the Lightsynq Plan were assumed by the Company. Such stock options granted under the Lightsynq Plan will continue to be governed by the terms of the Lightsynq Plan and the stock option agreements thereunder, until such outstanding options are exercised or until they terminate or expire. For awards granted under the Lightsynq Plan, vesting generally occurs over four years from the date of grant. As of December 31, 2025, the Company had no shares available for grant under the Lightsynq Plan.

Under each equity incentive plan, all options granted have a contractual term of 10 years.

Stock Options

The Company estimates the fair value of stock options on the date of grant using the Black-Scholes option-pricing model. The Black-Scholes option-pricing model requires estimates of highly subjective assumptions, which affect the fair value of each stock option. For stock options granted during the years ended December 31, 2025, 2024 and 2023, the assumptions for the Black-Scholes option-pricing model were developed as follows:

Expected Volatility—The expected volatility was based on the average historical stock price volatility of comparable publicly-traded companies in the Company's industry peer group, financial, and market capitalization data, due to the limited history of a public market for the Company's common stock relative to the expected term of the options.

Expected Term—The expected term of the Company’s options represents the period that the stock options are expected to be outstanding.

The Company has estimated the expected term of its employee stock option awards using the SAB Topic 14 Simplified Method allowed by the FASB and SEC for calculating expected term. Certain of the Company’s stock options began vesting prior to the grant date, in which case the Company uses the remaining vesting term at the grant date in the expected term calculation.

Risk-Free Interest Rate—The Company estimates its risk-free interest rate by using the yield on actively traded non-inflation-indexed U.S. treasury securities with contract maturities equal to the expected term.

Dividend Yield—The Company has not declared or paid dividends to date and does not anticipate declaring dividends. As such, the dividend yield has been estimated to be zero.

Fair Value of Underlying Common Stock—The Company utilizes the closing stock price on the date of grant as the fair value of the common stock underlying such stock options in the Black-Scholes option-pricing model.

Restricted Stock Units

During the years ended December 31, 2025, 2024 and 2023, the Company released 206,316, 1,064,518 and 566,389 RSUs, respectively, related to the settlement of an accrued bonus liability.

Performance-Based Restricted Stock Units

From fiscal year 2023 to fiscal year 2025, the Company granted performance-based restricted stock unit awards (“PSU”) to certain officers, employees and consultants, which vest over approximately two to four years. The number of shares that can be earned ranges from 0% to 300% of the target number of shares, based on the Company’s achievement of certain performance goals, as well as

a stock price hurdle requirement for a portion of the awards. If the stock price hurdle is not met at the time the PSUs vest, the maximum PSU opportunity is limited to target (100%) performance.

During fiscal year 2025, the Company granted PSU awards to certain officers and employees, which vest over approximately two to three years. The number of shares that can be earned ranges from 0% to 200% of the target number of shares based on the Company’s achievement of certain performance goals.

The number of PSUs expected to vest and for which compensation cost has been recognized is based on the number of shares that the Company believes are probable of vesting as of December 31, 2025.

For those PSUs subject to the stock price hurdle, the fair value was determined using a Monte Carlo simulation model. For PSUs granted during the years ended December 31, 2025, 2024 and 2023, the assumptions for the Monte Carlo simulation model were developed as follows:

Expected Volatility—The expected volatility in 2025 and 2024 was determined based on the Company's historical and implied stock price volatility. The expected volatility in 2023 was based on the average historical stock price volatility of comparable publicly traded companies in the Company's industry peer group, financial, and market capitalization data, due to the limited history of a public market for the Company's common stock relative to the contractual term of the PSUs.

Contractual Term—The Company utilizes the remaining performance period on the date of grant as the contractual term, which represents the period that the PSUs are expected to be outstanding.

Risk-Free Interest Rate—The Company estimates its risk-free interest rate by using the yield on actively traded non-inflation-indexed U.S. treasury securities with contract maturities equal to the expected term.

Dividend Yield—The Company has not declared or paid dividends to date and does not anticipate declaring dividends. As such, the dividend yield has been estimated to be zero.

Fair Value of Underlying Common Stock—The Company utilizes the closing stock price on the date of grant as the fair value of the common stock underlying such PSUs in the Monte Carlo simulation model.

Restricted Stock

Stock-Based Compensation Expense

Unrecognized Stock-Based Compensation

Employee Stock Purchase Plan

In August 2021, the Company’s board of directors adopted the Employee Stock Purchase Plan (the “ESPP”), which was subsequently approved by the Company’s stockholders in September 2021, and became effective upon the closing of the Business Combination. The ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the U.S. Internal Revenue Code of 1986, as amended (the “Code”). The number of shares of Company common stock initially reserved for issuance under the ESPP was 5,354,000 shares. The ESPP provides for an annual increase on January 1 of each year and continuing through and including January 1, 2031, equal to the lesser of (i) 1% of the fully diluted shares of common stock outstanding on the last day of the prior fiscal year, (ii) 10,708,000 shares, or (iii) a lesser number of shares determined by the Company’s board of directors prior to such increase. As of January 1, 2026, the number of shares reserved for issuance under the ESPP increased by 5,067,361.

Under the terms of the ESPP, eligible employees can elect to acquire shares of the Company’s common stock through periodic payroll deductions during a series of offering periods. Purchases under the ESPP are affected on the last business day of each offering period at a 15% discount to the lower of closing price on that day or the closing price on the first day of the offering period. As of December 31, 2025, no shares of common stock had been issued under the ESPP and no offering period had been set by the board of directors.