Charles K. Dargan - 31 Dec 2025 Form 5 Insider Report for BIOLARGO, INC. (BLGO)

Role: Chief Financial Officer
Signature: /s/ John R. Browning, attorney-in-fact
Issuer symbol: BLGO
Transactions as of: 31 Dec 2025
Net transactions value: -$171,000
Form type: 5
Filing time: 03 Feb 2026, 14:53:29 UTC
Previous filing: 15 Aug 2024
Next filing: 03 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
DARGAN CHARLES K	Chief Financial Officer	18851 NE 29TH AVENUE, SUITE 700, AVENTURA	/s/ John R. Browning, attorney-in-fact	03 Feb 2026	0001112799

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	$0	+300,000	+6.5%	$0.000000	4,925,786	01 Feb 2025	Common Stock	300,000	$0.2536	Direct	F1, F2
transaction	BLGO	Option to Purchase Common Stock	Other	$171,000	-300,000	-6.1%	$0.5700	4,625,786	30 Sep 2025	Common Stock	300,000	$0.5700	Direct	F3
transaction	BLGO	Option to Purchase Common Stock	Award	$0	+1,005,882	+22%	$0.000000	5,631,668	30 Sep 2025	Common Stock	300,000	$0.1700	Direct	F4
holding	BLGO	Option to Purchase Common Stock						5,631,668	31 Dec 2025	Common Stock	0		Direct	F5, F6, F7, F8

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

Explanation of Responses:

Id	Content
F1	The Option vests in equal monthly installments of 25,000 shares, so long as the Agreement between Reporting Person and Issuer remains in force and effect.
F2	This Option was issued to the Reporting Person as compensation to serve as Issuer's Chief Financial Officer from February 1, 2025, through January 31, 2026.
F3	The derivative security expired unexercised.
F4	This Option was granted to Reporting Person to replace an option to purchase 300,000 shares that expired September 30, 2025 to compensate Reporting Person for services to the Issuer and had expired unexercised due to a discrepancy between the original exercise price and current Issuer stock price, pursuant to plan adopted by the Issuer's Compensation Committee.
F5	Exercise prices vary.
F6	All options may be exercised (are fully vested) as of the date of this Report.
F7	Expiration dates vary.
F8	Reflects total beneficial ownership by Reporting Person of Options to Purchase Common Stock of the Issuer as of the end of Issuer's most recent fiscal year (December 31, 2025).