Company: REVB
Filing Date: 2025-04-04
Form Type: DRS
Source: 0001213900-25-029022
Chunk: 204

Company: REVELATION BIOSCIENCES, INC.
Filing Date: 2025-04-04
Form: DRS
Chunk 204
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| Granted                          |     |      — |     |           |        — |     |             |
| Exercised                        |     |      — |     |           |        — |     |             |
| Expired and forfeited            |     |      — |     |           |        — |     |             |
| Outstanding at December 31, 2024 |     |     64 |     | $         | 3,555.83 |     |         5.8 |
| Exercisable at December 31, 2024 |     |     64 |     | $         | 3,555.83 |     |         5.8 |

For the year ended December 31, 2023, the weighted -averageBlack -Scholesvalue per stock option issued during 2023 was $516.21. The fair value of the stock options was estimated using the Black -Scholesoption pricing model with the following weighted -averageassumptions:

| Volatility              |     | 144.2 | % |
| Expected term (years)   |     |  5.04 |   |
| Risk-free interest rate |     |  3.60 | % |
| Expected dividend yield |     |   0.0 | % |

Expected volatility is based on the historical volatility of shares of the Company’s common stock. In determining the expected term of stock options, the Company uses the “simplified” method. Under this method, the expected term is presumed to be the midpoint between the average vesting date and the end of the contractual term. The risk -freeinterest rate is based on the U.S. Treasury yield for a period consistent with the expected term of the stock options in effect at the time of the grants. The dividend yield assumption is based on the expectation of no future dividend payments by the Company. In addition to assumptions used in the Black -Scholesmodel, the Company reduces stock -basedcompensation expense based on actual forfeitures in the period that each forfeiture occurs.

F-19

REVELATION BIOSCIENCES, INC. Notes to the Consolidated Financial Statements 9. Stock-Based Compensation (cont.) Stock-Based Compensation Expense For the years ended December 31, 2024 and 2023, the Company recorded stock -basedcompensation expense for the period indicated as follows:

|                                                             |     | Year Ended   
 December 31, |    2024 |     |   |