ETON PHARMACEUTICALS INC ETON
COM · Common Stock · CUSIP 29772L108
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersDeer Park, IL
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($57.7k this quarter). Holder counts are more reliable. Shares outstanding: 28.6m as of 2026-08-11, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $36.19. Options: 4 managers hold calls ($4.8m notional), 5 hold puts ($4.1m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 33 |
| Q4 2022 | 32 |
| Q1 2023 | 36 |
| Q2 2023 | 34 |
| Q3 2023 | 51 |
| Q4 2023 | 57 |
| Q1 2024 | 45 |
| Q2 2024 | 46 |
| Q3 2024 | 49 |
| Q4 2024 | 72 |
| Q1 2025 | 87 |
| Q2 2025 | 88 |
| Q3 2025 | 103 |
| Q4 2025 | 104 |
| Q1 2026 | 116 |
| Q2 2026 | 165 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 22 | 18 |
| Q4 2024 | 51 | 14 |
| Q1 2025 | 54 | 33 |
| Q2 2025 | 61 | 44 |
| Q3 2025 | 52 | 39 |
| Q4 2025 | 48 | 56 |
| Q1 2026 | 62 | 49 |
| Q2 2026 | 112 | 41 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $2.4m | $281.7k | 0.12 |
| Q4 2025 | $1.8m | $10.1k | 0.01 |
| Q1 2026 | $4.2m | $3.3m | 0.80 |
| Q2 2026 | $4.8m | $4.1m | 0.85 |
Biggest buyers
| Nantahala Capital Management, LLC | Added | +1.2m |
| Nuveen, LLC | Added | +317.8k |
| MORGAN STANLEY | Added | +290.0k |
| D. E. Shaw & Co., Inc. | New | +188.5k |
| BlackRock, Inc. | Added | +178.5k |
| STATE STREET CORP | Added | +171.6k |
| MARSHALL WACE, LLP | Added | +166.5k |
| Prospect Capital Advisors, LLC | New | +157.2k |
| Woodline Partners LP | Added | +140.2k |
| Informed Momentum Co LLC | Added | +109.4k |
Biggest sellers
| CANNELL CAPITAL LLC | Reduced | -171.2k |
| Soleus Capital Management, L.P. | Sold out | -166.4k |
| RENAISSANCE TECHNOLOGIES LLC | Reduced | -111.0k |
| THOMPSON SIEGEL & WALMSLEY LLC | Reduced | -108.9k |
| UBS Group AG | Reduced | -103.5k |
| GOLDMAN SACHS GROUP INC | Reduced | -84.9k |
| Diametric Capital, LP | Reduced | -83.8k |
| CITADEL ADVISORS LLC | Reduced | -58.8k |
| PRELUDE CAPITAL MANAGEMENT, LLC | Reduced | -51.2k |
| XTX Topco Ltd | Reduced | -45.8k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $3.2m89.3k shares |
| JANE STREET GROUP, LLC | Added | $785.5k21.7k shares |
| IMC-Chicago, LLC | Reduced | $423.5k11.7k shares |
| SIMPLEX TRADING, LLC | Reduced | $405.4k11.2k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $1.6m43.4k shares |
| CITADEL ADVISORS LLC | Added | $1.3m36.4k shares |
| SIMPLEX TRADING, LLC | Reduced | $680.6k18.8k shares |
| JANE STREET GROUP, LLC | Reduced | $452.5k12.5k shares |
| GROUP ONE TRADING LLC | Unchanged | $79.6k2.2k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| EcoR1 Capital, LLC 13G · institution filed 2025-02-14 | 7.7% |
| BlackRock, Inc. 13G · institution +1.2 pts · filed 2026-07-28 | 6.9% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-26)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 0 | — | 2 | $4.1m | — |
| Q3 2025 | 0 | — | 1 | $673.7k | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 0 | — | 0 | — | — |
| Q2 2026 | 0 | — | 3 | $8.7m | — |
| Q3 2026 | 0 | — | 3 | $10.7m | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-08-28 | MAIER PAUL V Director | Sold | $3.0m50.0k shares |
| 2026-08-24 | Krempa David Chief Business Officer | Sold | $1.6m25.0k shares |
| 2026-08-20 | BRYNJELSEN SEAN President & CEO, director | Sold | $5.5m91.0k shares |
| 2026-08-19 | BRYNJELSEN SEAN President & CEO, director | Sold | $562.5k9.0k shares |
| 2026-07-14 | Opaleye Management Inc. 10% owner · By Opaleye, L.P. | Sold | $563.1k15.0k shares |
| 2026-07-14 | Opaleye Management Inc. 10% owner · By Managed Account | Sold | $499.8k13.3k shares |
| 2026-07-07 | Opaleye Management Inc. 10% owner · By Opaleye, L.P. | Sold | $767.4k20.0k shares |
| 2026-07-07 | Opaleye Management Inc. 10% owner · By Managed Account | Sold | $256.5k6.7k shares |
| 2026-07-06 | Opaleye Management Inc. 10% owner · By Opaleye, L.P. | Sold | $380.0k10.0k shares |
| 2026-07-02 | Opaleye Management Inc. 10% owner · By Opaleye, L.P. | Sold | $2.4m65.0k shares |
| 2026-07-02 | Opaleye Management Inc. 10% owner · By Managed Account | Sold | $934.8k25.0k shares |
| 2026-06-17 | Adams Jennifer McKie Director | Sold | $1.6m50.0k shares |
| 2026-05-28 | BRYNJELSEN SEAN President & CEO, director | Sold | $3.8m120.0k shares |
| 2026-05-27 | Krempa David Chief Business Officer | Sold | $619.3k19.7k shares |
| 2026-05-26 | Krempa David Chief Business Officer | Sold | $1.2m37.5k shares |
| 2026-05-22 | Krempa David Chief Business Officer | Sold | $1.4m42.8k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| Opaleye Management Inc. 9.38% of their portfolio | 2.9m $103.5m | Unchanged |
| Nantahala Capital Management, LLC 2.58% of their portfolio | 2.4m $85.1m | Added +1.2m |
| EcoR1 Capital, LLC 3.90% of their portfolio | 2.2m $78.6m | Unchanged |
| BlackRock, Inc. 0.00% of their portfolio | 1.9m $68.6m | Added +178.5k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 976.6k $35.4m | Reduced -17.5k |
| MORGAN STANLEY 0.00% of their portfolio | 768.0k $27.8m | Added +290.0k |
| STATE STREET CORP 0.00% of their portfolio | 701.8k $25.4m | Added +171.6k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 652.3k $23.6m | Added +74.6k |
| OBERWEIS ASSET MANAGEMENT INC/ 0.38% of their portfolio | 501.6k $18.2m | Added +62.3k |
| National Philanthropic Trust 0.26% of their portfolio | 492.1k $17.8m | Unchanged |
| Westside Investment Management, Inc. 2.05% of their portfolio | 431.2k $15.6m | Reduced -36.8k |
| Pillsbury Lake Capital LLC 3.85% of their portfolio | 387.2k $14.0m | Added +22.2k |
| Nuveen, LLC 0.00% of their portfolio | 375.7k $13.6m | Added +317.8k |
| BNP PARIBAS FINANCIAL MARKETS 0.01% of their portfolio | 322.5k $11.7m | Added +20.4k |
| Woodline Partners LP 0.03% of their portfolio | 310.9k $11.3m | Added +140.2k |
| THOMPSON SIEGEL & WALMSLEY LLC 0.19% of their portfolio | 297.2k $10.8m | Reduced -108.9k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 255.8k $9.3m | Added +18.0k |
| MARSHALL WACE, LLP 0.01% of their portfolio | 249.2k $9.0m | Added +166.5k |
| Panoramic Capital, LLC 3.24% of their portfolio | 208.2k $7.5m | Added +23.2k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 194.6k $7.0m | Added +42.8k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 191.6k $7.0m | Added +21.8k |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 188.5k $6.8m | New |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 185.7k $6.7m | Added +90.3k |
| Lumbard & Kellner, LLC 1.93% of their portfolio | 175.9k $6.4m | Reduced -2 |
| CANNELL CAPITAL LLC 4.32% of their portfolio | 170.7k $6.2m | Reduced -171.2k |
| NORGES BANK 0.00% of their portfolio | 169.5k $6.1m | Not comparable |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 168.5k $6.1m | Added +3.8k |
| Informed Momentum Co LLC 0.51% of their portfolio | 158.0k $5.7m | Added +109.4k |
| Prospect Capital Advisors, LLC 2.58% of their portfolio | 157.2k $5.7m | New |
| Aristides Capital LLC 1.35% of their portfolio | 145.4k $5.3m | Reduced -40.6k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 142.3k $5.1m | Reduced -2.1k |
| PRELUDE CAPITAL MANAGEMENT, LLC 0.37% of their portfolio | 137.6k $5.0m | Reduced -51.2k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 132.6k $4.8m | Reduced -84.9k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 118.2k $4.3m | Added +7.0k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 116.3k $4.2m | Added +9.9k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 114.7k $4.2m | Added +105.1k |
| WASATCH ADVISORS LP 0.02% of their portfolio | 92.7k $3.4m | New |
| Bridge City Capital, LLC 0.73% of their portfolio | 88.1k $3.2m | Added +67.0k |
| Walleye Capital LLC 0.01% of their portfolio | 86.2k $3.1m | Added +4.3k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 77.0k $2.8m | Added +8.2k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 76.1k $2.8m | Added +6.0k |
| Diametric Capital, LP 0.28% of their portfolio | 73.1k $2.6m | Reduced -83.8k |
| Numerai GP LLC 0.21% of their portfolio | 70.1k $2.5m | Added +32.8k |
| UBS Group AG 0.00% of their portfolio | 65.4k $2.4m | Reduced -103.5k |
| Squarepoint Ops LLC 0.00% of their portfolio | 59.6k $2.2m | New |
| BOOTHBAY FUND MANAGEMENT, LLC 0.04% of their portfolio | 57.5k $2.1m | Added +1.9k |
| BARCLAYS PLC 0.00% of their portfolio | 56.2k $2.0m | Added +6.8k |
| HighTower Advisors, LLC 0.00% of their portfolio | 52.9k $1.9m | Added +34.5k |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 52.3k $1.9m | Reduced -111.0k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 49.0k $1.8m | Reduced -58.8k |
| POLEN CAPITAL MANAGEMENT LLC 0.01% of their portfolio | 45.4k $1.6m | Added +15.2k |
| Point72 Asset Management, L.P. 0.00% of their portfolio | 44.9k $1.6m | New |
| Aquatic Capital Management LLC 0.05% of their portfolio | 43.8k $1.6m | Added +31.7k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 42.5k $1.5m | New |
| HSBC HOLDINGS PLC 0.00% of their portfolio | 41.0k $1.5m | New |
| ANCHOR CAPITAL ADVISORS LLC 0.04% of their portfolio | 40.6k $1.5m | Reduced -239 |
| SEI INVESTMENTS CO 0.00% of their portfolio | 34.7k $1.3m | Reduced -23.3k |
| Jefferies Financial Group Inc. 0.01% of their portfolio | 34.0k $1.2m | New |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 33.7k $1.2m | Added +3.0k |
| Y-Intercept (Hong Kong) Ltd 0.02% of their portfolio | 33.5k $1.2m | New |
| Invesco Ltd. 0.00% of their portfolio | 33.4k $1.2m | Added +10.5k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 32.8k $1.2m | Added +24.7k |
| BLAIR WILLIAM & CO/IL 0.00% of their portfolio | 32.4k $1.2m | Added +19 |
| Riggs Asset Managment Co. Inc. 0.21% of their portfolio | 32.0k $1.2m | New |
| Sigma Planning Corp 0.03% of their portfolio | 30.0k $1.1m | New |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 29.1k $1.1m | Added +17.2k |
| JUNCTURE WEALTH STRATEGIES, LLC 0.27% of their portfolio | 28.8k $1.0m | Added +9.7k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 28.2k $697.2k | New |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 26.5k $960.1k | Added +5.4k |
| STRS OHIO 0.00% of their portfolio | 23.6k $854.3k | New |
| Guilbault Capital LLC 0.85% of their portfolio | 23.5k $849.3k | Added +235 |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 21.9k $794.0k | Added +4.3k |
| PRUDENTIAL FINANCIAL INC 0.00% of their portfolio | 21.1k $765.0k | New |
| CITIGROUP INC 0.00% of their portfolio | 21.0k $758.5k | Added +18.4k |
| ESSEX INVESTMENT MANAGEMENT CO LLC 0.10% of their portfolio | 20.1k $728.7k | Reduced -51 |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 19.5k $707.5k | Added +900 |
| FIRST TRUST ADVISORS LP 0.00% of their portfolio | 19.5k $705.1k | New |
| NAVELLIER & ASSOCIATES INC 0.05% of their portfolio | 18.0k $652.0k | New |
| BANK OF NOVA SCOTIA 0.00% of their portfolio | 17.2k $622.6k | Added +2.2k |
| CHICAGO TRUST Co NA 0.09% of their portfolio | 16.7k $604.5k | Unchanged |
| Man Group plc 0.00% of their portfolio | 16.2k $584.7k | New |
| Gotham Asset Management, LLC 0.00% of their portfolio | 16.0k $578.5k | New |
| LOS ANGELES CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 15.7k $567.4k | Added +5.4k |
| MetLife Investment Management, LLC 0.00% of their portfolio | 15.7k $567.4k | Added +136 |
| ACADIAN ASSET MANAGEMENT LLC 0.00% of their portfolio | 15.0k $541.0k | New |
| PDT Partners, LLC 0.03% of their portfolio | 14.9k $539.1k | Unchanged |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 14.5k $525.1k | Reduced -19.6k |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 14.2k $512.8k | Added +5.2k |
| LPL Financial LLC 0.00% of their portfolio | 14.0k $507.4k | New |
| Connor, Clark & Lunn Investment Management Ltd. 0.00% of their portfolio | 13.2k $476.0k | Reduced -29.5k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 12.4k $450.5k | Added +194 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 12.3k $445.1k | Added +258 |
| Legato Capital Management LLC 0.03% of their portfolio | 11.5k $417.1k | New |
| Quantum Private Wealth, LLC 0.11% of their portfolio | 11.5k $416.3k | Unchanged |
| Menard Financial Group LLC 0.21% of their portfolio | 10.6k $385.2k | New |
| &PARTNERS 0.00% of their portfolio | 10.0k $362.0k | New |
| MACKENZIE FINANCIAL CORP 0.00% of their portfolio | 9.6k $347.2k | New |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 9.6k $346.9k | Reduced -1.2k |
| BRC Group Holdings, Inc. 0.08% of their portfolio | 9.4k $339.7k | New |
| Virtu Financial LLC 0.01% of their portfolio | 9.1k $329.0k | New |