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 ($43.6k this quarter). Holder counts are more reliable. Shares outstanding: 27.3m as of 2026-03-17, 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 ≈ $24.66. Options: 6 managers hold calls ($4.2m notional), 5 hold puts ($3.3m).
Trends to Q1 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 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q2 2024 | 13 | 22 |
| 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 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $4.5m | $169.6k | 0.04 |
| Q3 2025 | $2.4m | $281.7k | 0.12 |
| Q4 2025 | $1.8m | $10.1k | 0.01 |
| Q1 2026 | $4.2m | $3.3m | 0.80 |
Biggest buyers
| Pillsbury Lake Capital LLC | New | +365.0k |
| Panoramic Capital, LLC | New | +185.0k |
| Soleus Capital Management, L.P. | New | +166.4k |
| PRELUDE CAPITAL MANAGEMENT, LLC | Added | +143.5k |
| EcoR1 Capital, LLC | Added | +141.4k |
| CANNELL CAPITAL LLC | Added | +125.1k |
| MARSHALL WACE, LLP | New | +82.7k |
| Walleye Capital LLC | New | +82.0k |
| Woodline Partners LP | Added | +75.2k |
| SEI INVESTMENTS CO | New | +58.0k |
Biggest sellers
| Jefferies Financial Group Inc. | Sold out | -118.3k |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | Sold out | -84.0k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -64.4k |
| Russell Investments Group, Ltd. | Reduced | -47.0k |
| RENAISSANCE TECHNOLOGIES LLC | Reduced | -42.4k |
| Diametric Capital, LP | Reduced | -36.2k |
| Connor, Clark & Lunn Investment Management Ltd. | Reduced | -33.9k |
| BlackRock, Inc. | Reduced | -21.6k |
| WELLS FARGO & COMPANY/MN | Reduced | -18.7k |
| Bank of New York Mellon Corp | Reduced | -16.4k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $2.0m79.6k shares |
| SIMPLEX TRADING, LLC | Added | $770.0k31.2k shares |
| JANE STREET GROUP, LLC | Reduced | $513.3k20.8k shares |
| IMC-Chicago, LLC | New | $355.4k14.4k shares |
| CITADEL ADVISORS LLC | Added | $343.1k13.9k shares |
| GROUP ONE TRADING LLC | Added | $222.1k9.0k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | New | $1.6m66.1k shares |
| CITADEL ADVISORS LLC | New | $740.4k30.0k shares |
| SIMPLEX TRADING, LLC | Added | $481.3k19.5k shares |
| JANE STREET GROUP, LLC | New | $427.0k17.3k shares |
| GROUP ONE TRADING LLC | Added | $54.3k2.2k 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 in Q1 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 |
|---|---|---|---|---|---|
| Q2 2024 | 0 | — | 0 | — | — |
| Q3 2024 | 0 | — | 0 | — | — |
| 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 | — | — |
None reported in Q1 2026.
Holders, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| Opaleye Management Inc. 9.31% of their portfolio | 2.9m $70.6m | Unchanged |
| EcoR1 Capital, LLC 2.29% of their portfolio | 2.2m $53.6m | Added +141.4k |
| BlackRock, Inc. 0.00% of their portfolio | 1.7m $42.4m | Reduced -21.6k |
| Nantahala Capital Management, LLC 1.81% of their portfolio | 1.2m $29.0m | Unchanged |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 994.1k $24.5m | First filing |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 577.7k $14.3m | Added +12.6k |
| STATE STREET CORP 0.00% of their portfolio | 530.2k $13.1m | Added +28.3k |
| National Philanthropic Trust 0.13% of their portfolio | 492.1k $12.1m | Unchanged |
| MORGAN STANLEY 0.00% of their portfolio | 478.0k $11.8m | Reduced -16.0k |
| Westside Investment Management, Inc. 1.77% of their portfolio | 467.9k $11.5m | Reduced -3.0k |
| OBERWEIS ASSET MANAGEMENT INC/ 0.32% of their portfolio | 439.3k $10.8m | Added +8.0k |
| THOMPSON SIEGEL & WALMSLEY LLC 0.18% of their portfolio | 406.1k $10.0m | Reduced -2.5k |
| Pillsbury Lake Capital LLC 4.08% of their portfolio | 365.0k $9.0m | New |
| CANNELL CAPITAL LLC 5.48% of their portfolio | 342.0k $8.4m | Added +125.1k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 302.1k $7.5m | Added +24.6k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 237.8k $5.9m | Added +6.0k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 217.4k $5.4m | Added +21.2k |
| PRELUDE CAPITAL MANAGEMENT, LLC 0.36% of their portfolio | 188.8k $4.7m | Added +143.5k |
| Aristides Capital LLC 1.52% of their portfolio | 186.0k $4.6m | Added +24.6k |
| Panoramic Capital, LLC 3.21% of their portfolio | 185.0k $4.6m | New |
| Lumbard & Kellner, LLC 1.50% of their portfolio | 175.9k $4.3m | Added +967 |
| Woodline Partners LP 0.02% of their portfolio | 170.7k $4.2m | Added +75.2k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 169.9k $3.8m | Reduced -15.6k |
| UBS Group AG 0.00% of their portfolio | 169.0k $4.2m | Added +42.3k |
| Soleus Capital Management, L.P. 0.17% of their portfolio | 166.4k $4.1m | New |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 164.7k $4.1m | First filing |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 163.3k $4.0m | Reduced -42.4k |
| Diametric Capital, LP 1.01% of their portfolio | 156.9k $3.9m | Reduced -36.2k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 151.7k $3.7m | First filing |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 144.4k $3.6m | Added +39.6k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 111.3k $2.7m | Reduced -16.4k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 107.8k $2.7m | Added +33.7k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 106.4k $2.6m | Added +29.8k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 95.4k $2.4m | Added +37.4k |
| MARSHALL WACE, LLP 0.00% of their portfolio | 82.7k $2.0m | New |
| Walleye Capital LLC 0.01% of their portfolio | 82.0k $2.0m | New |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 70.1k $1.7m | Reduced -11.1k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 68.8k $1.7m | Reduced -8.4k |
| SEI INVESTMENTS CO 0.00% of their portfolio | 58.0k $1.4m | New |
| Nuveen, LLC 0.00% of their portfolio | 58.0k $1.4m | Reduced -967 |
| BOOTHBAY FUND MANAGEMENT, LLC 0.03% of their portfolio | 55.6k $1.4m | New |
| XTX Topco Ltd 0.02% of their portfolio | 51.8k $1.3m | Added +19.2k |
| BARCLAYS PLC 0.00% of their portfolio | 49.4k $1.2m | Reduced -2.1k |
| Informed Momentum Co LLC 0.14% of their portfolio | 48.6k $1.2m | New |
| Connor, Clark & Lunn Investment Management Ltd. 0.00% of their portfolio | 42.7k $1.1m | Reduced -33.9k |
| ANCHOR CAPITAL ADVISORS LLC 0.03% of their portfolio | 40.9k $1.0m | Added +190 |
| Manatuck Hill Partners, LLC 0.32% of their portfolio | 40.0k $987.2k | New |
| Numerai GP LLC 0.09% of their portfolio | 37.4k $921.9k | New |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 34.1k $841.2k | New |
| BLAIR WILLIAM & CO/IL 0.00% of their portfolio | 32.4k $799.6k | Unchanged |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 30.7k $758.3k | Added +290 |
| POLEN CAPITAL MANAGEMENT LLC 0.01% of their portfolio | 30.1k $743.8k | New |
| Guilbault Capital LLC 0.63% of their portfolio | 23.2k $573.2k | Unchanged |
| Invesco Ltd. 0.00% of their portfolio | 22.9k $564.5k | Added +3.2k |
| Brevan Howard Capital Management LP 0.01% of their portfolio | 22.5k $555.4k | New |
| Bridge City Capital, LLC 0.14% of their portfolio | 21.1k $522.0k | Added +2.5k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 21.1k $521.6k | Added +2.9k |
| ESSEX INVESTMENT MANAGEMENT CO LLC 0.08% of their portfolio | 20.2k $498.1k | Unchanged |
| JUNCTURE WEALTH STRATEGIES, LLC 0.16% of their portfolio | 19.2k $473.4k | Added +185 |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 18.6k $460.1k | Reduced -6.0k |
| HighTower Advisors, LLC 0.00% of their portfolio | 18.4k $454.7k | New |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 17.7k $436.0k | Added +2.3k |
| CHICAGO TRUST Co NA 0.07% of their portfolio | 16.7k $412.2k | Unchanged |
| MetLife Investment Management, LLC 0.00% of their portfolio | 15.5k $383.5k | Unchanged |
| BANK OF NOVA SCOTIA 0.00% of their portfolio | 15.0k $365.3k | New |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 14.9k $368.7k | Reduced -64.4k |
| PDT Partners, LLC 0.02% of their portfolio | 14.9k $367.5k | Unchanged |
| Voleon Capital Management LP 0.01% of their portfolio | 13.3k $328.0k | Reduced -2.3k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 12.2k $302.3k | Unchanged |
| Aquatic Capital Management LLC 0.01% of their portfolio | 12.1k $297.7k | Reduced -10.7k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 12.0k $297.1k | Added +174 |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 11.9k $294.3k | New |
| Quantum Private Wealth, LLC 0.09% of their portfolio | 11.5k $283.8k | Unchanged |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 10.7k $265.0k | Reduced -205 |
| LOS ANGELES CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 10.3k $253.4k | Reduced -4.4k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 9.6k $235.9k | Reduced -18.7k |
| State of Wyoming 0.03% of their portfolio | 9.5k $234.4k | Added +1.3k |
| Vanguard Global Advisers, LLC 0.00% of their portfolio | 9.0k $221.9k | First filing |
| Granite Investment Partners, LLC 0.01% of their portfolio | 8.5k $209.3k | New |
| Jain Global LLC 0.00% of their portfolio | 8.3k $204.5k | New |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 8.1k $199.9k | Unchanged |
| Quantbot Technologies LP 0.01% of their portfolio | 7.8k $192.2k | Reduced -1.6k |
| NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO 0.00% of their portfolio | 7.5k $185.1k | Reduced -2.5k |
| Police & Firemen's Retirement System of New Jersey 0.00% of their portfolio | 7.2k $177.9k | Unchanged |
| State of Alaska, Department of Revenue 0.00% of their portfolio | 6.9k $171.0k | Unchanged |
| China Universal Asset Management Co., Ltd. 0.01% of their portfolio | 4.8k $117.5k | Added +389 |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 2.7k $65.9k | Reduced -47.0k |
| CITIGROUP INC 0.00% of their portfolio | 2.5k $62.9k | Added +1.1k |
| Legal & General Group Plc 0.00% of their portfolio | 2.3k $57.5k | Reduced -401 |
| Ameritas Investment Partners, Inc. 0.00% of their portfolio | 2.2k $53.5k | Unchanged |
| FMR LLC 0.00% of their portfolio | 1.5k $37.5k | Reduced -1.6k |
| Mirae Asset Global Investments Co., Ltd. 0.00% of their portfolio | 1.4k $34.5k | Added +96 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 1.4k $34.3k | Reduced -190 |
| Truvestments Capital LLC 0.01% of their portfolio | 1.2k $29.2k | Unchanged |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 1.2k $28.5k | Reduced -1.8k |
| GF FUND MANAGEMENT CO. LTD. 0.00% of their portfolio | 597 $14.7k | Added +70 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 368 $9.1k | New |
| JONES FINANCIAL COMPANIES LLLP 0.00% of their portfolio | 350 $8.1k | Added +129 |
| Parallel Advisors, LLC 0.00% of their portfolio | 303 $7.5k | New |
| SBI Securities Co., Ltd. 0.00% of their portfolio | 263 $6.5k | Added +253 |