Dennis E. Marshall - 31 Dec 2025 Form 4 Insider Report for BIOLARGO, INC. (BLGO)

Role: Director
Signature: /s/ John R. Browning, attorney-in-fact
Issuer symbol: BLGO
Transactions as of: 31 Dec 2025
Net transactions value: $0
Form type: 4
Filing time: 05 Jan 2026, 16:30:38 UTC
Previous filing: 02 Oct 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Marshall Dennis E	Director	14921 CHESTNUT ST., WESTMINSTER	/s/ John R. Browning, attorney-in-fact	05 Jan 2026	0001361115

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	BLGO	Option to Purchase Common Stock	Award		+122,084	+2.4%		5,144,645	31 Dec 2025	Common Stock	122,084	$0.1843	Direct	F1, F2
transaction	BLGO	Option to Purchase Common Stock	Award		+101,736	+2%		5,246,381	31 Dec 2025	Common Stock	101,736	$0.1700	Direct	F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	This Option was granted to Reporting Person to replace an option to purchase 45,000 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.
F2	Total reflects the expiration of options to purchase 45,000 shares that recently expired.
F3	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.