Sean Brynjelsen - 12 Jan 2026 Form 4 Insider Report for Eton Pharmaceuticals, Inc. (ETON)

Reporting relationship: President & CEO, Director, 10%+ Owner
Issuer ticker: ETON
Reported as of: 12 Jan 2026
Net transaction value: -$77,181
SEC form: 4
Accepted by SEC: 14 Jan 2026, 18:04:50 UTC
Prior SEC filing: 12 Dec 2025
Next SEC filing: 29 May 2026
Source filing: View source filing
Reporting owner signature: /s/ James R. Gruber

Key filing fact

Sean Brynjelsen filed Form 4 for Eton Pharmaceuticals, Inc. (ETON) on 14 Jan 2026.

Key facts

This page summarizes Sean Brynjelsen's Form 4 filing for Eton Pharmaceuticals, Inc. (ETON).
3 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 14 Jan 2026, 18:04.

Change

Previous filing in this sequence was filed on 12 Dec 2025.
Current net transaction value: -$77,181.

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 0001669976 Primary reporting owner

BRYNJELSEN SEAN

Relationship: President & CEO, Director, 10%+ Owner
Address: C/O ETON PHARMACEUTICALS, INC., 21925 W. FIELD PARKWAY, SUITE 235, DEERPARK
Signature: /s/ James R. Gruber
Signature date: 14 Jan 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

ETON transaction

Common Stock

Tax liability

Transaction value: $77,181
Shares: -5,015
Change %: -0.17%
Price: $15.39
Shares after: 2,889,266
Date: 01 Jan 2026
Ownership: Direct
Footnotes: F1, F2, F3

Reported derivative securities

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

ETON transaction Derivative

Employee Stock Option (Right to Buy)

Award

Transaction value: $0
Shares: +158,046
Change %: +5.5%
Price: $0.000000
Shares after: 3,047,312
Date: 12 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 158,046
Exercise price: $15.47
Footnotes: F4

ETON transaction Derivative

Restricted Stock Units

Award

Transaction value: $0
Shares: +100,517
Change %: +3.3%
Price: $0.000000
Shares after: 3,147,829
Date: 12 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 100,517
Exercise price
Footnotes: F5, F6

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 6 footnotes

Footnote F1

Shares withheld by the Issuer to satisfy applicable withholding taxes upon the vesting of restricted stock units.

Footnote F2

The shares were sold in multiple trades at prices ranging from $15.39 to $15.42. The price reported above reflects the weighted average sales price.

Footnote F3

The Reporting Person will provide upon request by the Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price.

Footnote F4

The shares subject to the option shall vest in 48 equal monthly installments from the date of grant until fully vested and exercisable on January 12, 2030.

Footnote F5

Each restricted stock unit represents a contingent right to receive one share of ETON Common Stock.

Footnote F6

The restricted stock units vest in four equal annual installments beginning January 12, 2027, contingent upon the reporting person being employed by the issuer on the date(s) of vesting.

SEC remarks

The reporting person has authorized and designated the named person to file this Form 4 on the reporting person's behalf for indefinite duration.