Dennis E. Marshall - 31 Mar 2026 Form 4 Insider Report for BIOLARGO, INC. (BLGO)

Reporting relationship: Director
Issuer ticker: BLGO
Reported as of: 31 Mar 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 01 Apr 2026, 19:24:41 UTC
Prior SEC filing: 05 Jan 2026
Next SEC filing: 24 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ John R. Browning, attorney-in-fact

Key filing fact

Dennis E. Marshall filed Form 4 for BIOLARGO, INC. (BLGO) on 01 Apr 2026.

Key facts

This page summarizes Dennis E. Marshall's Form 4 filing for BIOLARGO, INC. (BLGO).
2 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 01 Apr 2026, 19:24.

Change

Previous filing in this sequence was filed on 05 Jan 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001361115 Primary reporting owner

Marshall Dennis E

Relationship: Director
Address: 14921 CHESTNUT ST., WESTMINSTER
Signature: /s/ John R. Browning, attorney-in-fact
Signature date: 01 Apr 2026

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

BLGO transaction Derivative

Option to Purchase Common Stock

Award

Transaction value
Shares: +138,889
Change %: +2.7%
Price
Shares after: 5,317,088
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 138,889
Exercise price: $0.1620
Footnotes: F1, F2

BLGO transaction Derivative

Option to Purchase Common Stock

Award

Transaction value
Shares: +115,741
Change %: +2.2%
Price
Shares after: 5,432,829
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 115,741
Exercise price: $0.1620
Footnotes: F3

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

This Option was granted to Reporting Person to replace an option to purchase 68,182 shares that had been issued to compensate Reporting Person for $22,500 in services to the Issuer and had 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.

Footnote F2

Total reflects the expiration of options to purchase 68,182 shares that expired March 31, 2026.

Footnote 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. The number of shares in the Option is equal to the amount of fees due divided by the exercise price of the Option.