ETON insider ownership: who sold, why, and what they still hold

What stands out

Four insiders sold $19.6M with no disclosed plan: Sean Brynjelsen ($9.9M), David Krempa ($5.1M) and Paul Maier ($3.0M), plus 1 more. The filings don't state a reason.Sean Brynjelsen: largest such sale, May 28, 2026 · David Krempa: largest such sale, Aug 24, 2026 · Paul Maier: largest such sale, Aug 28, 2026

Selling picked up in the last 90 days: officers and directors sold 179K shares, against an average of 88K per 90 days earlier in the period. Most of it was Sean Brynjelsen (100K shares in the last 90 days) and Paul Maier (50K shares in the last 90 days); 0% of these sales were under disclosed plans.Sean Brynjelsen: largest recent sale, Aug 20, 2026 · Paul Maier: largest recent sale, Aug 28, 2026

A share of stake is shown for 0 of the 4 officers and directors who sold. 10 are left out

Left out: Sean Brynjelsen, David Krempa, James Gruber, Norbert Riedel, Danka Radosavljevic, Paul Maier, Charles Casamento, Jennifer Adams, Ipek Erdogan-Trinkaus and Judith Matthews (share of stake is being verified).

Disclosed company stock is not an insider's whole wealth.

Who sold, and how much of their stake

Officers and directors, past 12 months. Their share of stake is being verified and is not shown yet; amounts and trading plans are below.

Sean Brynjelsen

President & CEO, Director

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$9.9MNo plan disclosed

David Krempa

Chief Business Officer

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$5.1MNo plan disclosed

Paul Maier

Director

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$3.0MNo plan disclosed

Jennifer Adams

Director

Not confirmed

Share of stake not shown: share of stake is being verified. Why

$1.6MNo plan disclosed

Amounts, filings and trading plans for each seller

Selling by month

Officers and directors, Oct 2025 to Oct 2026. Each sale is counted once: under a disclosed plan, else to cover taxes, else no plan disclosed.

No plan disclosedOne dollar scale for every month; the tallest bar is labeled

Recent activity

Past 30 days, Sep 17, 2026 to Oct 16, 2026

Oct 6, 2026David Krempa sold 4.2K shares ($229K) with no plan disclosed.

Who	Shares	Price	% of total stake	Total stake after	Trade date	Filed
David Krempa Chief Business Officer	4,166	$55.07	n/a	n/a	Oct 6, 2026	Oct 6, 2026

"% of total stake" is the shares in an event against all the vested shares the person held that day, across every share class and holding entity, after that day's vesting. "n/a" means the person's holdings are not confirmed, or the row is a purchase. "Holdings record incomplete" means more shares were sold than the filings show the person held that day, so a percentage would be wrong.

Outside holders, reported separately

Opaleye Management Inc. sold $5.8M in the past 12 months. Large shareholders and the funds or companies that board members represent are not part of management, so they are left out of the figures above.

Details

Common questions

Is the Eton Pharmaceuticals, Inc. CEO selling stock?

Yes. Sean Brynjelsen sold 220K shares ($9.9M) in the past 12 months, none of it under a trading plan disclosed in the filings.

Why are Eton Pharmaceuticals, Inc. insiders selling?

Filings rarely give a reason, and we don't guess at one. What they show is how the sales were made: 0% of sales by value ran under 10b5-1 trading plans disclosed in the filings and 100% had no disclosed plan. A trading plan schedules sales in advance.

Are any Eton Pharmaceuticals, Inc. insiders buying?

No. Officers and directors reported no purchases in the past 12 months.

The evidence

Who sold4 officers and directors: amount, % of holdings, trading plan

Who sold	Amount	% of holdings	Trading plan
Sean Brynjelsen President & CEO, Director	$9.9M 220K shares	Not confirmed share of stake is being verified. Why	No plan disclosed
David Krempa Chief Business Officer	$5.1M 129K shares	Not confirmed share of stake is being verified. Why	No plan disclosed
Paul Maier Director	$3.0M 50K shares	Not confirmed share of stake is being verified. Why	No plan disclosed
Jennifer Adams Director	$1.6M 50K shares	Not confirmed share of stake is being verified. Why	No plan disclosed

Outside holder, reported separately: Opaleye Management Inc. (a 10% owner, not part of management). Sold $5.8M (155K shares) from Jul 2, 2026 to Jul 14, 2026. Latest filing

The full ownership picture0 of 10 officers and directors confirmed

Vested shares across all share classes, held directly and through trusts, LLCs and family members, as reported on SEC Forms 3, 4 and 5. Unvested awards and options are never counted as owned shares.

Insider

Held Oct 16, 2025

Sold

Held Oct 16, 2026

Still held

Sean Brynjelsen

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. See the filing Sales and other transactions for Sean Brynjelsen are complete.

President & CEO, Director

n/a

−220K

n/a

Vesting, gifts, unvested awards and holding lines for Sean Brynjelsen

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Sean Brynjelsen are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−12Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
2,473,014	$4.42	Feb 12, 2034	$125M
107,469	$13.00	Jan 2, 2035	$4.5M
3,047,312	$15.47	Jan 11, 2036	$121M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

David Krempa

Chief Business Officer

n/a

−129K

n/a

Vesting, gifts, unvested awards and holding lines for David Krempa

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for David Krempa are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−8.2Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
813,430	$4.42	Feb 12, 2034	$41.2M
38,621	$13.00	Jan 2, 2035	$1.6M
670,893	$15.47	Jan 11, 2036	$26.6M
118,406	$3.58	Mar 11, 2030	$6.1M
70,000	$7.31	Feb 19, 2029	$3.3M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

James Gruber

Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for James Gruber are complete.

Chief Financial Officer

n/a

Vesting, gifts, unvested awards and holding lines for James Gruber

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for James Gruber are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−6.8Kwithheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
374,763	$4.42	Feb 12, 2034	$19.0M
38,621	$13.00	Jan 2, 2035	$1.6M
254,075	$15.47	Jan 11, 2036	$10.1M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

Norbert Riedel

Director

n/a

Vesting, gifts, unvested awards and holding lines for Norbert Riedel

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Norbert Riedel are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
164,555	$4.42	Feb 12, 2034	$8.3M
25,000	$13.00	Jan 2, 2035	$1.1M
286,496	$15.47	Jan 11, 2036	$11.3M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

Danka Radosavljevic

Chief Operating Officer

n/a

Vesting, gifts, unvested awards and holding lines for Danka Radosavljevic

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Danka Radosavljevic are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
31,508	$15.47	Jan 11, 2036	$1.2M
14,317	$13.00	Jan 2, 2035	$602K
10,000	$14.68	Mar 17, 2035	$404K
92,993	$4.42	Feb 12, 2034	$4.7M
10,000	$4.74	Aug 14, 2033	$503K
42,224	$3.47	Feb 19, 2033	$2.2M
35,000	$8.61	May 2, 2031	$1.6M
60,000	$3.58	Mar 11, 2030	$3.1M
18,742	$1.38	Jul 23, 2027	$1.0M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

Paul Maier

Director

n/a

−50K

n/a

Vesting, gifts, unvested awards and holding lines for Paul Maier

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Paul Maier are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
164,555	$4.42	Feb 12, 2034	$8.3M
25,000	$13.00	Jan 2, 2035	$1.1M
286,496	$15.47	Jan 11, 2036	$11.3M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

Charles Casamento

Director

n/a

Vesting, gifts, unvested awards and holding lines for Charles Casamento

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Charles Casamento are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
164,555	$4.42	Feb 12, 2034	$8.3M
25,000	$13.00	Jan 2, 2035	$1.1M
295,171	$15.47	Jan 11, 2036	$11.7M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

Jennifer Adams

Director

n/a

−50K

n/a

Vesting, gifts, unvested awards and holding lines for Jennifer Adams

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Jennifer Adams are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
133,133	$4.42	Feb 12, 2034	$6.7M
25,000	$13.00	Jan 2, 2035	$1.1M
170,329	$15.47	Jan 11, 2036	$6.7M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

Ipek Erdogan-Trinkaus

Chief Commercial Officer

n/a

Vesting, gifts, unvested awards and holding lines for Ipek Erdogan-Trinkaus

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Ipek Erdogan-Trinkaus are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

−85withheld by the company for taxes

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
75,000	$12.46	Dec 1, 2027	$3.2M
123,878	$15.47	Jan 11, 2036	$4.9M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

Judith Matthews

Chief Financial Officer

n/a

Vesting, gifts, unvested awards and holding lines for Judith Matthews

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Judith Matthews are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
37,000	$26.05	Apr 12, 2036	$1.1M

Estimate: options held × ($55.07 − strike price), using the most recent insider trade price on Form 4 (Oct 6, 2026), not a market close.

Holdings and share of stake for Eton Pharmaceuticals, Inc. are being verified, so no balances, unit counts or percentages are shown. Sales, proceeds, plan and tax status, titles and dates come straight from individual filings.

What explains the selling$19.6M of sales by plan status, purpose, seller and month

Officer and director open-market sales: $19.6M across 449,166 shares. Plan status and stated purpose are separate questions, and a sale can have both.

By plan status

No plan disclosed · $19.6M

Sales with no 10b5-1 plan and no tax reference in the filing. $9.9M of it is Sean Brynjelsen. No plan disclosed is a statement about the filing, not about why the sale happened. Largest such sale: Sean Brynjelsen, May 28, 2026

Taxes

26,873 shares ($441K) were withheld by the company for taxes, which isn't a market sale.

Seller	Shares sold	Proceeds	Under a disclosed plan	Share of total	Sales dates
Sean Brynjelsen President & CEO, Director	220K	$9.9M	0%	51%	May 28, 2026 to Aug 20, 2026
David Krempa Chief Business Officer	129K	$5.1M	0%	26%	May 22, 2026 to Oct 6, 2026
Paul Maier Director	50K	$3.0M	0%	15%	Aug 28, 2026 to Aug 28, 2026
Jennifer Adams Director	50K	$1.6M	0%	8%	Jun 17, 2026 to Jun 17, 2026

Sales by month

Month	Sale proceeds	Disclosed plan	To cover taxes	No plan disclosed
Oct 2025	$0	$0	$0	$0
Nov 2025	$0	$0	$0	$0
Dec 2025	$0	$0	$0	$0
Jan 2026	$0	$0	$0	$0
Feb 2026	$0	$0	$0	$0
Mar 2026	$0	$0	$0	$0
Apr 2026	$0	$0	$0	$0
May 2026	$7.1M	$0	$0	$7.1M
Jun 2026	$1.6M	$0	$0	$1.6M
Jul 2026	$0	$0	$0	$0
Aug 2026	$10.7M	$0	$0	$10.7M
Sep 2026	$0	$0	$0	$0
Oct 2026	$229K	$0	$0	$229K

Is this normal? Selling year by year5 earlier years to compare with

More than usual: $19.6M sold, after almost none in the past 5 years. 4 insiders sold; the average is 1 a year.

12 months ending	Shares sold	Insiders who sold	Proceeds
Oct 16, 2026 Latest 12 months	449K	4	$19.6M
Oct 16, 2025 1 year earlier	286K	3	$4.8M
Oct 16, 2024 2 years earlier	0	0	$0
Oct 17, 2023 3 years earlier	0	0	$0
Oct 17, 2022 4 years earlier	0	0	$0
Oct 17, 2021 5 years earlier	0	0	$0

Open-market sales (Form 4 code S) by people who were officers or directors, in split-adjusted shares. Earlier years include people who have since left. A sale that an outside holder also reports (a family trust, a fund) is counted with outside holders in every year. Shares, not dollars, are compared, so a change in the stock price doesn't look like a change in selling. Years the filings don't fully cover are shown but left out of the average.

Known gaps and uncertainty10 officers and directors not confirmed

Holdings and share of stake are being verified. Balances, unit counts and every share-of-stake figure for Eton Pharmaceuticals, Inc. are held back until that check is finished. Sales, proceeds, plan and tax status, titles and dates come straight from individual filings and are complete.

External context: we only cite outside events when a documented connection exists. None is shown for this period.

Sources and methodology131 filings on record, 38 filed in the 12-month period, and how we read them

All 131 Forms 3, 4 and 5 on record for Eton Pharmaceuticals, Inc. (SEC CIK 1710340), filed from Nov 13, 2018 to Oct 6, 2026; 38 of them were filed in the 12 months this page covers, retrieved from SEC EDGAR on Oct 16, 2026. Prices are the ones reported in each filing, often weighted averages.

Holdings. Each holding line (a share class plus an owner, such as a trust or LLC) carries its last reported balance forward. Entities first reported during the period start at zero, so transfers between an insider's own trusts don't count as selling. Lines not reported for three years or more are listed separately and left out of totals.

Sales. A sale counts as under a 10b5-1 plan if its footnote cites one or the filing's Rule 10b5-1 box is checked, and as tax-related if its footnote cites tax obligations or sell-to-cover. Shares withheld by the company for taxes are listed separately. Sales with neither attribute are labeled "no plan disclosed".

Full methodology

Former or inactive filers (3)No filing in 18 months; last reported balances, not in any total

Name	Last filed	Last reported balance
William Troutman	Feb 28, 2022	23,027 shares, last reported balance as of Aug 20, 2021
HARROW HEALTH, INC.	Apr 12, 2021	1,982,000 shares, last reported balance as of Apr 12, 2021
Mark Baum	Mar 16, 2020	794,745 shares, last reported balance as of Nov 15, 2018

Spotted something wrong on this page? Report an error. We check every report against the SEC filing and list what we fix in the corrections log.

Eton Pharmaceuticals, Inc. insiders sold $19.6M in the past 12 months. How much of their stake is that?

What stands out

Who sold, and how much of their stake

Selling by month

Recent activity

Outside holders, reported separately

Common questions

Is the Eton Pharmaceuticals, Inc. CEO selling stock?

Why are Eton Pharmaceuticals, Inc. insiders selling?

Are any Eton Pharmaceuticals, Inc. insiders buying?

The evidence

No plan disclosed · $19.6M

Taxes

Sales by month