X0508 4 2025-03-05 0001534969 SERA PROGNOSTICS, INC. SERA 0001870674 Boniface John J. C/O SERA PROGNOSTICS, INC. 2749 EAST PARLEYS WAY, SUITE 200 SALT LAKE CITY UT 84109 false true false false Chief Scientific Officer false Class A Common Stock 2025-03-05 4 A false 47010 0 A 172894 D Class A Common Stock 2025-03-06 4 S false 2044 4.16 D 170850 D Stock Option (right to buy) 4.2 2025-03-05 4 A false 67810 0 A 2035-03-05 Class A Common Stock 67810 67810 D Each share is represented by a restricted stock unit ("RSU"). These RSUs vest over four years as follows: 1/16 of the original grant amount vests in quarterly installments for four years following the vesting commencement date, which is March 10, 2025, subject to the Reporting Person continuing to provide services to the issuer. Represents the number of shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units ("RSUs"). The sale is mandated by the Issuer's election to require the satisfaction of tax withholding obligations to be funded by "sell to cover" transactions and does not represent a discretionary transaction by the Reporting Person. The price reported is a weighted average price. These shares were sold as part of a block trade in multiple transactions at prices ranging from $4.07 to $4.24, inclusive. The Reporting Person will provide to the staff of the Securities and Exchange Commission, the issuer, or any security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price with regard to the block trade. These stock options vest over four years as follows: 1/48 of the original grant amount vests in monthly installments for four years following the vesting commencement date, which is March 10, 2025, subject to the Reporting Person continuing to provide services to the issuer. /s/ Benjamin G. Jackson, Attorney-in-fact 2025-03-07