Eton Pharmaceuticals Inc
Ownership
Ownership Structure
Who owns Eton Pharmaceuticals Inc (ETON)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 78.0% of the shares are freely tradable; institutional investors hold 65.4%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Opaleye Management Inc | 10.01 | 2,860,000 | +0.0 | 06/30/2026 |
| EcoR1 Capital, LLC | 7.60 | 2,171,938 | +0.0 | 06/30/2026 |
| BlackRock Inc | 6.01 | 1,717,286 | -1.2 | 03/31/2026 |
| Nantahala Capital Management, LLC | 4.11 | 1,175,951 | +0.0 | 03/31/2026 |
| Vanguard Capital Management, LLC | 3.48 | 994,089 | +0.0 | 03/31/2026 |
| Geode Capital Management, LLC | 2.02 | 577,666 | +2.2 | 03/31/2026 |
| State Street Corp | 1.86 | 530,215 | +5.6 | 03/31/2026 |
| Oberweis Asset Management Inc | 1.75 | 501,600 | +14.2 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.44 | 696,981 | +1.8 | 07/31/2026 |
| iShares Russell 2000 ETF | 2.39 | 683,555 | -0.6 | 08/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Opaleye Management Inc. | 10% Owner | 2,705,000 | 150,127,500 $ | Jul 14, 2026 | indirect |
| Brynjelsen Sean | President & CEO | 961,194 | 53,346,267 $ | Aug 20, 2026 | direct |
| Maier Paul V | Director | 59,745 | 3,315,848 $ | Aug 28, 2026 | direct |
| Krempa David | Chief Business Officer | 37,025 | 2,054,888 $ | Aug 24, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 28, 2026 | Maier Paul V | Director | Sell | 128 | 61.77 | 7,907 |
| Aug 28, 2026 | Maier Paul V | Director | Sell | 13,485 | 60.21 | 811,932 |
| Aug 28, 2026 | Maier Paul V | Director | Sell | 36,387 | 58.64 | 2,133,734 |
| Aug 28, 2026 | Maier Paul V | Director | Other | 50,000 | 3.78 | 189,000 |
| Aug 24, 2026 | Krempa David | Chief Business Officer | Sell | 25,000 | 65.07 | 1,626,750 |
| Aug 24, 2026 | Krempa David | Chief Business Officer | Other | 25,000 | 7.31 | 182,750 |
| Aug 20, 2026 | Brynjelsen Sean | President & CEO | Sell | 7,342 | 62.12 | 456,085 |
| Aug 20, 2026 | Brynjelsen Sean | President & CEO | Sell | 36,373 | 61.11 | 2,222,754 |
| Aug 20, 2026 | Brynjelsen Sean | President & CEO | Sell | 47,307 | 60.17 | 2,846,462 |
| Aug 19, 2026 | Brynjelsen Sean | President & CEO | Sell | 8,978 | 62.65 | 562,472 |
| Jul 14, 2026 | Opaleye Management Inc. | 10% Owner | Sell | 13,315 | 37.54 | 499,886 |
| Jul 14, 2026 | Opaleye Management Inc. | 10% Owner | Sell | 15,000 | 37.54 | 563,147 |
| Jul 14, 2026 | Brynjelsen Sean | President & CEO | Other | 200,000 | 1.37 | 274,000 |
| Jul 12, 2026 | Brynjelsen Sean | President & CEO | Other | 27,500 | – | – |
| Jul 12, 2026 | Krempa David | Chief Business Officer | Other | 10,000 | – | – |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 18, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.