Note 15.  Stock-Based Compensation

Equity Award Plan

Old SES established its initial share incentive plan in 2013 (the “2013 Plan”), which was subsequently replaced with a new share incentive plan in 2018 (the “2018 Plan”). Under the terms of the 2013 Plan and 2018 Plan, certain number of shares were reserved for the issuance of incentive stock options (“ISOs”) and non-statutory stock options (“NSOs”) to employees, officers, directors, consultants and advisors. On March 30, 2021, the Company amended the 2018 Plan with the SES Holdings Pte. Ltd. 2021 Share Incentive Plan (the “2021 Plan”) and increased the total shares reserved for future issuance by 486,975 shares. Upon approval of the 2021 Plan, any shares that, as of the date of stockholder approval, were reserved but not issued pursuant to any awards granted under the Company’s 2018 Plan were rolled into the 2021 Plan. In addition, any shares issued pursuant to or subject to stock options or similar awards granted under the 2018 Plan that expired or otherwise terminated without having been exercised in full or that were forfeited or repurchased by the Company, rolled into the 2021 Plan. The 2021 Plan provided for the discretionary grant of ISOs, NSOs, and Restricted Share Awards (“RSAs”).

In connection with the Business Combination, the 2021 Plan was terminated and the remaining unallocated share reserve was cancelled, and no new awards will be granted under the 2021 Plan. At Closing, a total of 20,748,976 ISOs and NSOs and 2,273,727 RSAs (as converted, due to retroactive application of reverse recapitalization) outstanding under the 2021 Plan were assumed by the Company under the SES AI Corporation 2021 Plan (defined below).

SES AI Corporation 2021 Plan

In connection with the Business Combination, the Company adopted the SES AI Corporation 2021 Incentive Award Plan (the “SES 2021 Plan”) under which 36,862,002 shares of Class A common stock were initially reserved for issuance of ISOs, NSOs, stock appreciation rights (“SARs”), RSAs, restricted stock units (“RSUs”), performance compensation awards (“PSUs”), other stock-based and cash-based awards, and dividend equivalents. In addition, and subject to certain limitations, any shares issued pursuant to or subject to awards granted under the 2021 Plan that expired or otherwise terminated without having been exercised in full or that were forfeited or repurchased by the Company, rolled into the SES 2021 Plan. The SES 2021 Plan allows for the maximum number of shares issuable to automatically increase on January 1st of each year for a period of ten years commencing on January 1, 2023 and ending on (and including) January 1, 2031, in an amount equal to two percent of the total number of shares of stock outstanding on December 31st of the preceding year. As of December 31, 2024, 37,263,345 shares remain available for future issuance under the SES 2021 Plan.

Stock-Based Compensation Expense

Compensation expense related to stock-based awards was recorded as follows:

 

Years Ended December 31, 

(in thousands)

2024

    

2023

Research and development

$

8,021

$

3,796

General and administrative

 

11,896

16,853

Cost of revenue

 

18

Total

$

19,935

$

20,649

The following table summarizes share-based compensation expense by award type:

Years Ended December 31, 

(in thousands)

2024

    

2023

Earn-Out Restricted Shares

$

1,997

$

2,689

RSUs

12,733

9,644

PSUs

2,885

4,781

RSAs

1,950

3,133

Stock options

370

402

Total

$

19,935

$

20,649

 Restricted Stock Units

RSUs granted under the SES 2021 Plan vest in equal annual installments over a three-year period and have only service vesting conditions. The fair value of RSUs is estimated based on the closing price of the Company’s Class A common stock at the date of grant and is amortized to expense on a straight-line basis over the vesting period. RSU activity is as follows:

Number of Shares

Weighted Average Fair Value

Outstanding at December 31, 2022

2,807,660

$

8.61

Granted

5,365,427

$

2.25

Vested

(1,063,863)

$

8.41

Forfeited and canceled

(749,750)

$

4.95

Outstanding at December 31, 2023

6,359,474

$

3.71

Granted

11,729,289

$

1.32

Gross vested units

(2,413,455)

$

4.14

Forfeited and canceled

(2,392,385)

$

1.95

Outstanding at December 31, 2024

13,282,923

$

1.83

 

The total fair value of RSUs vested was $10.0 million and $8.9 million for the years ended December 31, 2024 and 2023, respectively.

As of December 31, 2024, there was $14.3 million of unrecognized compensation cost related to RSUs, which is expected to be recognized over a weighted-average period of 1.0 years.

Restricted Stock Awards

RSAs granted under the 2021 Plan and assumed under the SES 2021 Plan generally vest 1/4th upon completion of one year of service and 1/48th per month thereafter and have only service vesting conditions. The fair value of RSAs is estimated based on the closing price of the Company’s Class A common stock at the date of grant and is amortized to expense on a straight-line basis over the vesting period. RSA activity is as follows:

Number of Shares

Weighted Average Fair Value

Outstanding at December 31, 2022

1,270,726

$

5.09

Granted

$

-

Vested

(610,335)

$

5.14

Forfeited and canceled

(10,824)

$

5.13

Outstanding at December 31, 2023

649,567

$

5.05

Granted

$

Vested

(386,964)

$

5.05

Forfeited and canceled

(7,145)

$

5.07

Outstanding at December 31, 2024

255,458

$

5.04

 

The total fair value of RSAs vested was $2.0 million and $3.1 million for the years ended December 31, 2024 and 2023, respectively.

As of December 31, 2024, there was $1.2 million of unrecognized compensation cost related to RSAs, which is expected to be recognized over a weighted-average period of 0.3 years.

Performance Stock Units

PSUs granted under the SES 2021 Plan generally vest over a three-year period and have both service and market vesting conditions. PSUs are measured at their estimated fair value using a Monte Carlo simulation valuation model with the effect of the market condition reflected in the grant date fair value of the award. The fair value of PSU awards is amortized to expense on a straight-line basis over the requisite service period, irrespective of whether the market vesting condition is satisfied, which is generally two to three years. The key inputs used in the Monte Carlo simulation model for PSUs granted during the years ended December 31, 2024 and 2023 at their measurement date were as follows:

 

2024

    

2023

Expected term (in years)

3.0

5.0

Risk free rate

4.06%

3.57%

Expected volatility

90.0%

80.0%

Expected dividends

0%

0%

Stock price

$

1.36

$

2.25

The stock price is based on the closing price of the Company’s Class A common stock as of the valuation date and simulated through the end of the earn-out period following Geometric Brownian Motion. Expected volatility is based on the weighted average historical volatilities of the Company’s Class A common stock and select peer companies’ common stock that matches the expected term of the awards. The expected term is derived from the vesting period. The risk-free interest rate is based on the yield curve for zero-coupon U.S. Treasury notes with maturities corresponding to the expected term of the awards. The dividend rate is based on the historical rate, which the Company anticipates remaining at zero.

PSU activity is as follows:

Number of Shares

Weighted Average Fair Value

Outstanding at December 31, 2022

2,116,942

$

5.98

Granted

1,631,800

$

0.58

Vested

$

Forfeited and canceled

(383,932)

$

3.86

Outstanding at December 31, 2023

3,364,810

$

3.60

Granted

3,637,556

$

0.42

Vested

$

Forfeited and canceled

(1,029,316)

$

6.96

Outstanding at December 31, 2024

5,973,050

$

1.34

 

As of December 31, 2024, there was $1.8 million of unrecognized compensation cost related to PSUs, which is expected to be recognized over a weighted-average period of 1.5 years.

Earn-Out Restricted Shares

The Earn-Out Restricted Shares granted in connection with the Business Combination have a contractual term of five years and have both service and market vesting conditions. The Earn-Out Restricted Shares have been measured at their estimated fair value using a Monte Carlo simulation valuation model with the effect of the market condition reflected in the grant date fair value of the award. The aggregate grant date fair value of the Earn-Out Restricted Shares is $15.0 million and is amortized to expense on a straight-line basis over the requisite service period, irrespective of whether the market vesting condition is satisfied, which is 1.45 years. The key inputs used in the Monte Carlo simulation model for the Earn-Out Restricted Shares at their measurement dates were as follows:

February 3, 2022
(Closing Date)

Contractual term (in years)

5.0

Risk-free rate

1.63%

Expected volatility

81.0%

Expected dividends

0%

Stock price

$

7.68

 

The stock price is based on the closing price of the Company’s Class A common stock as of the valuation date and simulated through the end of the earn-out period following Geometric Brownian Motion. The Company estimates the volatility of its common stock by using select peer companies’ common stock that matches the contractual term of the awards. The risk-free interest rate is based on the yield curve for zero-coupon U.S. Treasury notes with maturities corresponding to the contractual term of the restricted shares. The dividend rate is based on the historical rate, which the Company anticipates remaining at zero.

Earn-Out Restricted Shares activity is as follows:

Number of Shares

Weighted Average Fair Value

Outstanding at December 31, 2022

1,931,044

$

6.53

Granted/vested

$

Forfeited and canceled

(311,046)

$

6.53

Outstanding at December 31, 2023

1,619,998

$

6.53

Granted/vested

$

Forfeited and canceled

(854,008)

$

6.53

Outstanding at December 31, 2024

765,990

$

6.53

 

During the year ended December 31, 2023, the Earn-Out Restricted Shares met the requisite service period and the related expense was fully amortized.

Stock Options

Options granted under the 2021 Plan and assumed under the SES 2021 Plan vest 1/4th upon completion of one year of service and 1/48th per month thereafter, however in certain instances options have been granted with immediate vesting. Options under the Plan generally expire 10 years from the date of grant and have only service vesting conditions. Stock option activity is as follows:

Number of Options

Weighted Average Exercise Price

Weighted Average Remaining Contractual Term
(in years)

Aggregate Intrinsic Value
(in millions)

Outstanding at December 31, 2022

18,308,233

$

0.17

7.6

$

54.6

Granted

$

Exercised

(3,691,340)

$

0.14

$

7.0

Forfeited and canceled

(997,100)

$

0.18

Outstanding at December 31, 2023

13,619,793

$

0.17

6.8

$

22.7

Granted

$

Exercised

(6,507,475)

$

0.16

$

4.0

Forfeited and canceled

(1,049,208)

$

0.19

Outstanding at December 31, 2024

6,063,110

$

0.19

5.5

$

12.2

Vested, December 31, 2024

5,848,933

$

0.18

5.5

$

11.8

Vested or expected to vest, December 31, 2024

6,063,110

$

0.19

5.5

$

12.2

 

No income tax benefit was recognized for stock options exercised as the Company does not anticipate realizing any such benefit in the near future. The fair value of stock options vested for the years ended December 31, 2024 and 2023 were $11.8 million and $16.4 million, respectively.

The Company uses the Black-Scholes pricing model to determine the fair value of options granted. The calculation of the fair value of stock options is affected by the stock price on the grant date, the expected volatility of the Company’s stock over the expected term of the award, the expected life of the award, the risk-free interest rate and the dividend yield. There were no options granted during the years ended December 31, 2024 and 2023.

As of December 31, 2024, there was less than $0.1 million of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted-average period of 0.1 years.

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.