Eton Pharmaceuticals ETON Insider Ownership

NASDAQ ETON

$48.99 -1.20 (-2.39%)

As of: Oct 21, 2026 · 11:39 AM EDT

Insider Holdings by Owner

4.06Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

14.43%

▲+0.217% pp QoQ

Shares Held by Insiders

4.08Mn

filed for Sep 2026

▲+1.53% QoQ

Shares Outstanding

28.29Mn

28,289,941 shares

Direct Holdings

1.35Mn

Indirect: 2.73Mn

Net Shares Traded (QoQ)

+61.52K

net buying in Sep 2026

Insiders Holding Shares

with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold

Latest quarter —

Net over range —

Buying quarters —

Insider Ownership Summary

Updated Oct 10, 2026

Over the past year, ETON insiders sold $25.41 million of stock (604.17K shares) on the open market and bought none.

By number of insiders, Eton Pharmaceuticals saw 5 insiders sell on the open market over the past 12 months and none buy.
Sean Brynjelsen (President & CEO) was ETON's largest open-market seller in the past 12 months, with $9.91 million of sales (220K shares); the latest was on August 20, 2026.
The newest open-market trade among Eton Pharmaceuticals insiders came on October 6, 2026, when David Krempa (Chief Business Officer) made a sale of 4.17K shares for $229,406.
Away from the open market, ETON insiders acquired 535.47K shares through option exercises and conversions and gave up 26.87K shares to cover taxes or exercise prices over the last 12 months.
Business Quant data shows Eton Pharmaceuticals insiders holding 4.09Mn shares in total in their latest Form 4 filings, up 1.69% from 4.02Mn shares at the end of Q2 2026.
Eton Pharmaceuticals insiders hold 1.36Mn shares directly (33.25% of their total) and 2.73Mn shares (66.75%) indirectly, through entities such as trusts and partnerships.
The insider holdings in Eton Pharmaceuticals belong to 7 insiders who have reported on Form 4 within the past two years.
Eton Pharmaceuticals' three largest insider shareholders, based on their latest Form 4 filings, are Opaleye Management Inc. (10% owner, 2.71Mn shares), Sean Brynjelsen (President & CEO, 986.13K shares) and James R. Gruber (Chief Financial Officer, 213.42K shares).
Opaleye Management Inc. holds 66.14% of the combined insider position in Eton Pharmaceuticals.
Institutions accounted for 70.54% of ETON's outstanding shares in Q2 2026, insiders about 14.46% per their latest Form 4 filings, and other investors, including the public, about 15.00%.
In the past year, 10 insiders of Eton Pharmaceuticals submitted 36 Form 4 filings reporting trades, awards or other transactions.
The insider data for ETON reflects Form 4 filings through October 6, 2026.

Form 4 Holdings

Insiders Holding ETON

Insiders 7

Shares held 4.06Mn

Of outstanding 14.37%

#	Insider	Position	Direct	Indirect	Total	Share of Insiders	Last Filed
1	Management Inc. Opaleye	TenPercentOwner	0	2,705,000	2,705,000	66.5%	17 Jul, 2026
2	Sean Brynjelsen	President Ceo	961,194	0	961,194	23.6%	20 Aug, 2026
3	James R. Gruber	Chief Financial Officer	213,420	0	213,420	5.3%	14 Jan, 2026
4	Paul V Maier	Director	72,245	0	72,245	1.8%	31 Aug, 2026
5	Norbert G Riedel	Director	67,155	0	67,155	1.7%	22 Apr, 2026
6	David Krempa	Chief Business Officer	43,381	0	43,381	1.1%	06 Oct, 2026
7	Ipek Erdogan-Trinkaus	Chief Commercial Officer	2,403	0	2,403	0.1%	12 Dec, 2025

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

232 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
02 Oct, 2026	David Krempa	Chief Business Officer	Acquired M	10,522	—	—	47,547	Direct
06 Oct, 2026	David Krempa	Chief Business Officer	Disposed S	4,166	$55.07	$229.41K	43,381	Direct
02 Oct, 2026	David Krempa	Chief Business Officer	Disposed M	10,522	$0.00	$0	21,044	Direct
28 Aug, 2026	Paul V Maier	Director	Acquired M	50,000	$3.78	$189.00K	109,745	Direct
28 Aug, 2026	Paul V Maier	Director	Disposed S	36,387	$58.64	$2.13Mn	73,358	Direct
28 Aug, 2026	Paul V Maier	Director	Disposed S	13,485	$60.21	$811.93K	59,873	Direct
28 Aug, 2026	Paul V Maier	Director	Disposed S	128	$61.77	$7.91K	59,745	Direct
28 Aug, 2026	Paul V Maier	Director	Acquired M	12,500	$7.31	$91.38K	72,245	Direct
28 Aug, 2026	Paul V Maier	Director	Disposed M	50,000	$0.00	$0	0	Direct
28 Aug, 2026	Paul V Maier	Director	Acquired M	12,500	$0.00	$0	0	Direct
28 Aug, 2026	Paul V Maier	Director	Acquired M	50,000	$3.78	$189.00K	109,745	Direct
28 Aug, 2026	Paul V Maier	Director	Disposed S	36,387	$58.64	$2.13Mn	73,358	Direct
28 Aug, 2026	Paul V Maier	Director	Disposed S	13,485	$60.21	$811.93K	59,873	Direct
28 Aug, 2026	Paul V Maier	Director	Disposed S	128	$61.77	$7.91K	59,745	Direct
28 Aug, 2026	Paul V Maier	Director	Disposed M	50,000	$0.00	$0	0	Direct
24 Aug, 2026	David Krempa	Chief Business Officer	Acquired M	25,000	$7.31	$182.75K	62,025	Direct
24 Aug, 2026	David Krempa	Chief Business Officer	Disposed S	25,000	$65.07	$1.63Mn	37,025	Direct
24 Aug, 2026	David Krempa	Chief Business Officer	Disposed M	25,000	$0.00	$0	70,000	Direct
19 Aug, 2026	Sean Brynjelsen	President Ceo	Disposed S	8,978	$62.65	$562.47K	1,052,216	Direct
20 Aug, 2026	Sean Brynjelsen	President Ceo	Disposed S	47,307	$60.17	$2.85Mn	1,004,909	Direct

Showing 1 to 20 of 232 transactions