SERA PROGNOSTICS, INC.

Insider Trading Arrangements and Policies:

The following table provides information concerning Rule 10b5-1 trading arrangements (as defined in Item 408 of Regulation S-K under the Exchange Act)adopted during the quarter ended June 30, 2025 by any director or executive officer who is subject to the filing requirements of Section 16 of the Exchange Act, or a Section 16 Director or Officer. These trading arrangements are intended to satisfy the affirmative defense of Rule 10b5-1(c). Certain of the Company’s Section 16 Directors or Officers may participate in the Company’s 2021 Employee Stock Purchase Plan, or the 2021 ESPP, that has been designed to comply with Rule 10b5-1(c). No non-Rule 10b5-1 trading arrangements (as defined in Item 408 of Regulation S-K under the Exchange Act) were adoptedbyany Section

16 Director or Officer during the quarter ended June 30, 2025. Additionally, Robert G. Harrison, Chief Information Officer, terminatedhis former Rule 10b5-1 trading arrangement on April 29, 2025. No other Rule 10b5-1 or non-Rule 10b5-1 trading arrangements were terminatedby any Section 16 Director or Officer during the quarter ended June 30, 2025.

(1)

Sales under the trading arrangement will not commence until the selling start date. Subject to compliance with Rule 10b5-1, duration could cease earlier than the final date shown above pursuant to the terms of the trading arrangement.

(2)

Sales under the trading arrangement exclude specified “No Sale” periods.

(3)

The 10b5-1 trading arrangement provides for the sale of up to (i) 535,425 shares of our Class A common stock plus (ii) the net number of shares of our Class A common stock underlying certain restricted stock unit, or RSU, awards. The number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is indeterminable with respect to the RSU awards, as such number is subject to the number of shares that will be automatically sold to satisfy applicable tax withholding obligations upon vesting of the RSU awards, which will vary based on the market price of our Class A common stock at the time of vesting.

(4)

The 10b5-1 trading arrangement provides for the sale of up to (i) 364,714 shares of our Class A common stock plus (ii) the net number of shares of our Class A common stock underlying certain RSU awards. The number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is indeterminable with respect to the RSU awards, as such number is subject to the number of shares that will be automatically sold to satisfy applicable tax withholding obligations upon vesting of the RSU awards, which will vary based on the market price of our Class A common stock at the time of vesting.

(5)

The 10b5-1 trading arrangement provides for the sale of up to (i) 167,168 shares of our Class A common stock plus (ii) the net number of shares of our Class A common stock underlying certain RSU awards. The number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is indeterminable with respect to the RSU awards, as such number is subject to the number of shares that will be automatically sold to satisfy applicable tax withholding obligations upon vesting of the RSU awards, which will vary based on the market price of our Class A common stock at the time of vesting.

(6)

The 10b5-1 trading arrangement provides for the sale of up to (i) 310,956 shares of our Class A common stock plus (ii) the net number of shares of our Class A common stock underlying certain RSU awards. The number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is indeterminable with respect to the RSU awards, as such number is subject to the number of shares that will be automatically sold to satisfy applicable tax withholding obligations upon vesting of the RSU awards, which will vary based on the market price of our Class A common stock at the time of vesting.