[Form 4] SERA PROGNOSTICS, INC. Insider Trading Activity

Rhea-AI Filing Summary

Harrison Robert Gardner, Chief Information Officer of SERA Prognostics, Inc. (SERA), reported a planned sale of 2,000 shares of Class A common stock executed on 10/07/2025 under a Rule 10b5-1 trading plan adopted on 05/21/2025. The shares were sold in multiple transactions at prices ranging from $3.04 to $3.28, with a reported weighted average price of $3.18. After this disposition, the reporting person beneficially owns 97,932 shares directly. The form is signed by an attorney-in-fact and notes that detailed per-trade information is available on request.

Positive

• Sale executed under a Rule 10b5-1 plan adopted on 05/21/2025, indicating pre-arranged timing
• Reporting person retains 97,932 shares after the transaction, showing continued material ownership

Negative

• Disposition of 2,000 shares reduces insider holdings and could modestly increase available float
• Sales occurred across multiple prices ($3.04–$3.28), which may reflect execution across trading sessions

Insights

Corporate Governance Analyst

Planned insider sale under a 10b5-1 plan; ownership remains material.

The sale was executed under a Rule 10b5-1 trading plan adopted on 05/21/2025, which provides an affirmative defense to insider trading restrictions when properly structured. The report shows 2,000 shares sold at a weighted average of $3.18, with prices ranging from $3.04 to $3.28.

Because the reporting person still holds 97,932 shares directly, this transaction appears to be a routine liquidity event rather than a full exit. Watch for any future pattern of sales or amendments to the 10b5-1 plan within the next 12 months for additional insight into insider liquidity behavior.

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)
10/07/2025

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	10/07/2025		S(1)		2,000	D	$3.18(2)	97,932	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 $3.04 to $3.28, 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	10/08/2025
	** 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 Harrison Gardner sell on 10/07/2025?

He sold 2,000 shares of Class A common stock at a weighted average price of $3.18 under a Rule 10b5-1 plan.

How many SERA shares does Harrison Gardner own after the sale?

The filing reports he beneficially owns 97,932 shares directly following the transaction.

Was the sale part of a pre-arranged trading plan?

Yes. The transaction was effected pursuant to a Rule 10b5-1 plan adopted on 05/21/2025.

At what prices were the shares sold?

Shares were sold in multiple transactions at prices ranging from $3.04 to $3.28, inclusive.

Who signed the Form 4?

The Form 4 was signed by Benjamin G. Jackson, attorney-in-fact, on 10/08/2025.