[Form 4] BIOLARGO, INC. Insider Trading Activity

Rhea-AI Filing Summary

Marshall Dennis E, a director of Biolargo, Inc. (BLGO), reported option grants on 09/30/2025. Two options to purchase common stock were acquired: 132,351 shares exercisable at $0.17 per share (expiring 09/30/2035) and 110,294 shares exercisable at $0.17 per share (expiring 09/30/2035). The first option replaces a previously issued option for 34,615 shares that expired unexercised; the replacement was made under the issuer’s Compensation Committee plan in lieu of $22,500 in services. The second option was issued as payment of $18,750 in board fees under the 2024 Equity Incentive Plan. Following the reported grants, beneficial ownership figures shown are 4,957,267 and 5,067,561 shares on the respective lines. The Form 4 was signed by attorney-in-fact John R. Browning on 10/02/2025.

Positive

• Director compensation delivered via equity preserves cash and aligns interests with shareholders
• Replacement option was approved by the Compensation Committee to rectify an expired grant

Negative

• Total potential dilution of 242,645 option shares exists if both grants are exercised
• Low exercise price of $0.17 may represent a favorable grant relative to market price

Insights

Corporate Governance Analyst

Director received equity-based compensation and a replacement option for an expired grant.

The filing shows the board compensates directors partly with stock options, including a replacement for an expired service-related option. That reflects use of equity to conserve cash and align director incentives with shareholders. The replacement of a previously expired option was authorized by the Compensation Committee, indicating internal governance approval.

Compensation & Dilution Specialist

Two option grants total 242,645 shares exercisable at $0.17, expiring in 2035.

The reporting person received 132,351 and 110,294 option shares at a $0.17 exercise price, issued as compensation for services totaling $40,250 in fees or replacement value. These grants increase potential share dilution if exercised; the filing lists updated beneficial ownership totals on each line which should be used to assess dilution versus outstanding shares.

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).

1. Name and Address of Reporting Person^*

Marshall Dennis E

(Last) (First) (Middle)

14921 CHESTNUT ST.

(Street)

WESTMINSTER CA 92683

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BIOLARGO, INC. [ BLGO ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
09/30/2025

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

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
Option to Purchase Common Stock	$0.17	09/30/2025		A		132,351		09/30/2025	09/30/2035	Common Stock	132,351	(1)	4,957,267(2)	D
Option to Purchase Common Stock	$0.17	09/30/2025		A		110,294		09/30/2025	09/30/2035	Common Stock	110,294	(3)	5,067,561	D

Explanation of Responses:

1. This Option was granted to Reporting Person to replace an option to purchase 34,615 shares that had been issued to compensate Reporting Person for $22,500 in services to the Issuer and had recently expired unexercised due to a discrepancy between the original exercise price and Issuer's current stock price, pursuant to plan adopted by the Issuer's Compensation Committee.

2. Total reflects the expiration of options to purchase 34,615 shares that recently expired.

3. This Option was issued to Reporting Person as payment for $18,750 in fees due to Reporting Person by Issuer in exchange for services on its board of directors for the most recently completed quarterly period, pursuant to the Issuer's 2024 Equity Incentive Plan.

	/s/ John R. Browning, attorney-in-fact	10/02/2025
	** 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 transactions did BLGO director Marshall Dennis E report on Form 4?

He reported two option grants on 09/30/2025: 132,351 and 110,294 options exercisable at $0.17, expiring 09/30/2035.

Why was one option granted as a replacement in the BLGO filing?

The replacement option substitutes an expired option for 34,615 shares that lapsed due to an exercise-price discrepancy; it was approved by the issuer’s Compensation Committee.

How much cash value was exchanged for the board compensation reflected in the Form 4?

The filing states $22,500 related to the replaced option and $18,750 for board fees, totaling $41,250 in service-related compensation.

What are the reported beneficial ownership totals after these transactions?

The Form 4 shows line totals of 4,957,267 and 5,067,561 shares on the respective reporting lines following the transactions.

Who signed the Form 4 on behalf of the reporting person and when?

The Form 4 was signed by attorney-in-fact John R. Browning on 10/02/2025.