[Form 4] Sera Prognostics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Insider sale under 10b5-1 plan: Robert Harrison, Chief Information Officer of Sera Prognostics, sold 2,000 shares of Class A common stock on 09/09/2025 at a weighted-average price of $3.05 per share under a Rule 10b5-1 trading plan adopted May 21, 2025. Following the reported sale, the reporting person beneficially owned 100,577 shares, held directly. The filing was signed by an attorney-in-fact on behalf of the reporting person.

Positive

• Transaction executed under a Rule 10b5-1 plan, indicating pre-scheduled, compliance-oriented trading
• Reporting person retains 100,577 shares after the sale, showing continued direct ownership

Negative

• Disposition of 2,000 shares reduced the reporting person's holdings
• Sales occurred across multiple prices ($2.99–$3.12), requiring weighted-average reporting rather than single-price disclosure

Insights

Corporate Governance Expert

TL;DR: A routine, pre-planned insider sale under a 10b5-1 plan reduced holdings modestly; no additional material disclosures included.

The Form 4 discloses a sale of 2,000 Class A shares by the Chief Information Officer executed pursuant to a Rule 10b5-1 plan adopted on May 21, 2025. The use of an established 10b5-1 plan indicates the transactions were scheduled and compliant with insider trading rules. The reporting person retains 100,577 shares after the sale. The filing provides a weighted-average sale price range ($2.99–$3.12) and notes availability of per-trade details upon request.

Securities Analyst

TL;DR: The sale is small relative to total holdings and appears procedural; it does not present new operational or financial information.

The disclosed transaction is a non-derivative disposition of 2,000 shares at a weighted-average price of $3.05, executed 09/09/2025. Post-transaction beneficial ownership remains 100,577 shares held directly. No options, grants, or other derivative instruments are reported. The filing contains standard explanatory language about the 10b5-1 plan and weighted-average pricing across multiple trades.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Harrison Robert Gardner

(Last) (First) (Middle)

C/O SERA PROGNOSTICS, INC.

2749 EAST PARLEYS WAY, SUITE 200

(Street)

SALT LAKE CITY UT 84109

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
SERA PROGNOSTICS, INC. [ SERA ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Information Officer

3. Date of Earliest Transaction (Month/Day/Year)
09/09/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	09/09/2025		S(1)		2,000	D	$3.05(2)	100,577	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The transaction(s) reported on this Form 4 was/were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 21, 2025.

2. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $2.99 to $3.12, 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.

	/s/ Benjamin G. Jackson, Attorney-in-fact	09/09/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did SERA insider Robert Harrison report on Form 4?

The filing reports a sale of 2,000 Class A shares on 09/09/2025 under a Rule 10b5-1 plan, at a weighted-average price of $3.05 per share.

How many SERA shares does the reporting person own after the transaction?

The reporting person beneficially owned 100,577 shares of Class A common stock following the reported sale.

Was the sale part of a prearranged trading plan?

Yes. The sale was effected pursuant to a Rule 10b5-1 trading plan adopted May 21, 2025.

What price range were the shares sold at?

The shares were sold in multiple transactions at prices ranging from $2.99 to $3.12; the form reports a weighted-average price of $3.05.

Does the Form 4 report any derivative transactions or option activity?

No. Table II for derivative securities shows no reported transactions or derivative holdings.