The Company has a 2015 Equity Incentive Plan (the “2015 Plan”), which provided for the grant of share-based compensation to certain officers, directors, employees, consultants, and advisors. Upon the closing of the Business Combination, no further awards were made pursuant to the 2015 Plan and all outstanding Legacy IonQ stock options under the 2015 Plan were assumed by the Company. Such stock options granted under the 2015 Plan will continue to be governed by the terms of the 2015 Plan and the stock option agreements thereunder, until such outstanding options are exercised or until they terminate or expire by their terms. For awards granted under the 2015 Plan, vesting generally occurs over four to five years from the date of grant.

In August 2021, the Company’s board of directors adopted the 2021 Equity Incentive Plan (the “2021 Plan”), which was subsequently approved by the Company’s stockholders in September 2021, and became effective upon the closing of the Business Combination. The 2021 Plan 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, beginning on January 1, 2022, and continuing 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, 2024, the number of shares reserved for issuance under the 2021 Plan increased by 14,215,808. For awards granted under the 2021 Plan, vesting terms range from one to four years from the date of grant. As of March 31, 2024, the Company had 25,096,978 shares available for grant under the 2021 Plan.

Under both equity incentive plans, all options granted have a contractual term of 10 years.

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 three months ended March 31, 2024 and 2023, the assumptions for the Black-Scholes option-pricing model were developed as follows:

Expected Volatility—As the Company was privately held until 2021 and there has been limited history of a public market for its common stock prior to closing the Business Combination, the expected volatility is based on the average historical stock price volatility of comparable publicly-traded companies in its industry peer group, financial, and market capitalization data.

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, as it has limited historical exercise data to provide a reasonable basis upon which to otherwise estimate 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.

The assumptions used to estimate the fair value of stock options granted are as follows:


	Three Months Ended March 31,
	2024			2023
Risk-free interest rate		4.31	%		—	%
Expected term (in years)		6.00			—
Expected volatility		79.33	%		—	%
Dividend yield		—	%		—	%

The stock option activity is summarized in the following table:


	Number of Option Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in millions)
Outstanding as of December 31, 2023		21,664,377		$	2.26
Granted		52,640			11.24
Exercised		(1,542,328	)		0.97
Cancelled/ Forfeited		—			—
Outstanding as of March 31, 2024		20,174,689		$	2.38		6.17	$	157.09
Exercisable as of March 31, 2024		14,582,299		$	1.57		5.70	$	124.52
Exercisable and expected to vest as of March 31, 2024		20,174,689		$	2.38		6.17	$	157.09

As of March 31, 2024 and December 31, 2023, there were 355,619 and 403,764 shares, respectively, subject to repurchase related to stock options early exercised and unvested. As of March 31, 2024 and December 31, 2023, the Company recorded a liability related to these shares subject to repurchase in the amount of $0.7 million and $0.8 million, respectively, in its condensed consolidated balance sheets.

The RSU activity is summarized in the following table:


	Number of RSUs			Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (Years)		Aggregate Fair Value (in millions)
Outstanding as of December 31, 2023		15,107,535		$	8.90
Granted		4,860,915			10.41
Vested		(2,741,447	)		8.71
Forfeited		(187,174	)		6.55
Outstanding as of March 31, 2024		17,039,829		$	9.39		2.96	$	170.23
Expected to vest after March 31, 2024		16,998,829		$	9.38		2.96	$	169.82

During the three months ended March 31, 2024 and 2023, the Company released 1,064,518 and zero RSUs, respectively, related to the settlement of an accrued bonus liability.

During the year ended December 31, 2023, the Company granted performance-based restricted stock unit awards (“PSU”) to certain officers and employees, which vest over approximately four years. The target number of PSUs granted was 4,641,564. The number of shares that can be earned will range from 0% to 300% of the target number of shares, based on the Company's achievement of certain financial and technical goals, as well as a stock price hurdle requirement for a portion of the awards. In the event that the stock price hurdle is not met at the time the PSUs vest, the maximum PSU opportunity shall be limited to target (100%) performance. The number of PSUs expected to vest and for which

compensation cost has been recognized is based on the number of awards that the Company believes are probable of vesting as of March 31, 2024.

For the portion of the PSUs subject to the stock price hurdle, the fair value was determined using a Monte Carlo simulation model. The Monte Carlo simulation model requires estimates of highly subjective assumptions, which affect the fair value of each PSU.

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.

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.

There were no PSUs granted during the three months ended March 31, 2024 and 2023.

The PSU activity is summarized in the following table, based on awards at target:


	Number of PSUs			Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (Years)		Aggregate Fair Value (in millions)
Outstanding as of December 31, 2023		4,307,833		$	15.75
Forfeited		(500,597	)		15.56
Outstanding as of March 31, 2024		3,807,236		$	15.78		2.92	$	38.03
Expected to vest after March 31, 2024(1)		5,710,854		$	15.09		2.92	$	57.05

(1)

Represents the number of PSUs expected to vest, which may exceed the target number of shares, based on the Company's probability assessment of expected performance during the performance period.

Total stock-based compensation expense for stock option awards, RSUs, and PSUs, which are included in the condensed consolidated financial statements, is as follows (in thousands):


	Three Months Ended March 31,
	2024		2023
Cost of revenue	$	1,005	$	349
Research and development		12,366		5,280
Sales and marketing		2,775		764
General and administrative		5,915		3,875
Stock-based compensation, net of amounts capitalized	$	22,061	$	10,268
Capitalized stock-based compensation—Intangibles and fixed assets		1,598		619
Total stock-based compensation	$	23,659	$	10,887

A summary of the Company's remaining unrecognized compensation expense and the weighted-average remaining amortization period as of March 31, 2024, related to its non-vested RSUs, PSUs, and stock option awards is presented below (in millions, except time period amounts):


	Unrecognized Expense		Weighted- Average Amortization Period (Years)
Restricted stock units	$	147.5		3.1
Performance-based restricted stock units		71.0		2.9
Stock options		23.6		2.0

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 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, beginning on January 1, 2022, 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. The board of directors elected not to approve the annual increase of ESPP shares on January 1, 2024.

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 March 31, 2024, no shares of common stock had been issued under the ESPP and no offering period had been set by the board of directors.