Company: REVB
Filing Date: 2025-05-20
Form Type: S-1
Source: 0001213900-25-045828
Chunk: 209

Company: REVELATION BIOSCIENCES, INC.
Filing Date: 2025-05-20
Form: S-1
Chunk 209
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| 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-free interest 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-Scholes model, the Company reduces stock-based
compensation 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-based compensation expense for the period indicated as follows:

|                                                             |     | Year Ended   
 December 31, |    2024 |     |   |    2023 |
|:------------------------------------------------------------|:----|:-------------|--------:|:----|:--|--------:|
| General and administrative:                                 |     |              |         |     |   |         |
| RSU awards                                                  |     | $            |  97,077 |     | $ |  89,533 |
| Stock Options                                               |     |              |  58,857 |     |   |  56,204 |
| General and administrative stock-based compensation expense |     |              | 155,934 |     |   | 145,737 |
| Research and development:                                   |     |              |         |     |   |         |
| RSU awards                                                  |     |              |   7,759 |     |   |   7,592 |
| Stock Options                                               |     |              |   5,157 |     |   |   2,392 |
| Research and development stock-based compensation expense   |     |              |