[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 sale of 6,000 shares of Class A common stock on 08/20/2025 under a pre-existing Rule 10b5-1 trading plan adopted May 21, 2025. The shares were sold at a weighted average price of $2.22, with executed prices ranging from $2.17 to $2.25. After the sales, the reporting person beneficially owned 102,577 shares directly. The Form 4 was filed by one reporting person and signed by an attorney-in-fact on the same date.

Positive

• Sale executed under a Rule 10b5-1 trading plan, providing preplanned timing and reducing concerns about opportunistic insider trading.
• Clear pricing disclosure including weighted average price $2.22 and execution range $2.17–$2.25 enhances transparency.
• Form 4 filed by one reporting person with signature (attorney-in-fact) on the transaction date, indicating timely reporting.

Negative

• Insider reduced direct holdings by 6,000 shares, leaving 102,577 shares, a decrease of approximately 5.9% of the reporting person's post-transaction stake.

Insights

Securities Analyst

TL;DR Insider sale of ~6% of holdings executed under a 10b5-1 plan; transaction is transparent but reduces insider stake.

The sale of 6,000 shares represents approximately 5.9% of the reporting person's post-transaction direct holdings of 102,577 shares. Because the disposition was executed pursuant to a Rule 10b5-1 trading plan adopted on May 21, 2025, timing is preplanned rather than opportunistic. The weighted average sale price of $2.22 with execution prices between $2.17 and $2.25 provides clear pricing context. For investors, this is a routine insider liquidity event rather than an operational signal, though it modestly lowers the CIO's direct ownership stake.

Corporate Governance Expert

TL;DR Pre-established trading plan mitigates governance concerns; disclosure is complete and conforms to Section 16 reporting.

The filing discloses a 10b5-1 plan and provides a weighted-average sale price plus the execution range and the plan adoption date, which are best practices for transparency. The Form 4 was signed by an attorney-in-fact and filed individually by the reporting person. There is no indication of derivative transactions or amendments. From a governance perspective, the disclosure reduces information asymmetry but highlights a modest reduction in insider ownership that governance stakeholders may note.

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)
08/20/2025

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	08/20/2025		S(1)		6,000	D	$2.22(2)	102,577	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 $2.17 to $2.25, 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	08/20/2025
	** 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 report on Form 4?

The reporting person sold 6,000 Class A shares on 08/20/2025 and now beneficially owns 102,577 shares.

Was the SERA sale part of a prearranged trading plan?

Yes. The sales were effected under a Rule 10b5-1 trading plan adopted on May 21, 2025.

At what price were the SERA shares sold?

The weighted average sale price was $2.22, with individual sale prices ranging from $2.17 to $2.25.

Who filed and signed the Form 4 for this SERA transaction?

The Form 4 was filed by one reporting person and signed by Benjamin G. Jackson, Attorney-in-fact on 08/20/2025.

Did the Form 4 report any derivative transactions?

No. The filing shows only a non-derivative sale of Class A common stock; Table II lists no derivative activity.