Omeros Corporation (OMER) Ownership
OMER ownership summary
as of October 18, 2026- Institutions
- 51.4% of shares outstanding
- Insiders
- 4.08% of shares outstanding
- Shares outstanding
- 72.4M
- Float
- 69.3M shares available to trade
- Short interest
- 16.30% 11.4M shares short
- Days to cover
- 7.54 short interest down 8.9% vs prior month
- Institutions 51.36%
- Insiders 4.08%
- Other investors 44.55%
OMER top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 8.35% | 6.0M | $97.9M | +735,007 (+13.8%) | June 30, 2026 |
| 2 | Ingalls & Snyder LLC | 5.06% | 3.7M | $59.3M | +100,100 (+2.8%) | June 30, 2026 |
| 3 | UBS Group AG | 4.35% | 3.1M | $51.0M | +807,653 (+34.5%) | June 30, 2026 |
| 4 | Vanguard Capital Management, LLC | 4.24% | 3.1M | $49.8M | +88,791 (+3.0%) | June 30, 2026 |
| 5 | State Street Corp | 3.20% | 2.3M | $37.6M | +400,331 (+20.9%) | June 30, 2026 |
| 6 | Geode Capital Management, LLC | 2.64% | 1.9M | $31.0M | +162,137 (+9.3%) | June 30, 2026 |
| 7 | Stifel Financial Corp | 2.54% | 1.8M | $29.8M | +5,340 (+0.3%) | June 30, 2026 |
| 8 | Vanguard Portfolio Management, LLC | 1.33% | 963K | $15.6M | +244,153 (+34.0%) | June 30, 2026 |
| 9 | Amvescap Plc. | 1.04% | 752K | $12.2M | +571,142 (+316.2%) | June 30, 2026 |
| 10 | Northern Trust Corp | 1.00% | 727K | $11.8M | +163,481 (+29.0%) | June 30, 2026 |
| 11 | Rock Springs Capital Management LP | 0.99% | 718K | $11.6M | +718,499 (0.0%) | June 30, 2026 |
| 12 | CI Private Wealth LLC | 0.91% | 660K | $10.7M | −141,681 (−17.7%) | June 30, 2026 |
| 13 | Rubric Capital Management LP | 0.91% | 657K | $10.6M | +656,874 (0.0%) | June 30, 2026 |
| 14 | Charles Schwab Investment Management Inc | 0.84% | 605K | $9.8M | +22,121 (+3.8%) | June 30, 2026 |
| 15 | Bank of Montreal | 0.79% | 568K | $9.2M | −2 (−0.0%) | June 30, 2026 |
| 16 | BMO Capital Markets Corp. | 0.79% | 568K | $9.2M | −2 (−0.0%) | June 30, 2026 |
| 17 | Vanguard Fiduciary Trust Co | 0.68% | 491K | $8.0M | −1,172 (−0.2%) | June 30, 2026 |
| 18 | Federated Hermes Inc | 0.66% | 478K | $7.7M | +478,290 (0.0%) | June 30, 2026 |
| 19 | Clutterbuck Capital Management LLC | 0.62% | 450K | $7.3M | +150,000 (+50.0%) | June 30, 2026 |
| 20 | Two Sigma Investments LLC | 0.56% | 403K | $6.5M | +116,188 (+40.6%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 16 holders added 5.4M shares and 4 cut 143K.
OMER top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 3.00% | 2.2M | $35.2M | — | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 2.58% | 1.9M | $30.2M | −21,504 (−1.1%) | September 30, 2026 |
| 3 | Fidelity Small Cap Index | 1.09% | 789K | $12.8M | +7,440 (+1.0%) | July 31, 2026 |
| 4 | State Street® SPDR® S&P® PhrmctlsETF | 0.74% | 537K | $8.7M | −6,674 (−1.2%) | September 30, 2026 |
| 5 | iShares Russell 2000 Value ETF | 0.58% | 420K | $6.8M | +636 (+0.2%) | September 30, 2026 |
| 6 | Vanguard Russell 2000 ETF | 0.58% | 419K | $6.8M | +4,958 (+1.2%) | September 30, 2026 |
| 7 | Schwab US Small-Cap ETF™ | 0.53% | 383K | $6.2M | +252 (+0.1%) | September 30, 2026 |
| 8 | Fidelity Extended Market Index | 0.49% | 352K | $5.7M | −5,520 (−1.5%) | August 31, 2026 |
| 9 | Vanguard US Momentum Factor ETF | 0.37% | 268K | $4.3M | +166,334 (+164.2%) | June 30, 2026 |
| 10 | iShares US Pharmaceuticals ETF | 0.36% | 264K | $4.3M | +811 (+0.3%) | September 30, 2026 |
| 11 | iShares Russell 2000 Growth ETF | 0.35% | 255K | $4.1M | −323 (−0.1%) | September 30, 2026 |
| 12 | iShares Micro-Cap ETF | 0.31% | 228K | $3.7M | −1,570 (−0.7%) | September 30, 2026 |
| 13 | Vanguard Health Care ETF | 0.29% | 211K | $3.4M | +228 (+0.1%) | September 30, 2026 |
| 14 | Heptagon Driehaus US Micro Cap Eq C$ Acc | 0.29% | 207K | $3.4M | +207,321 (0.0%) | August 31, 2026 |
| 15 | Federated Hermes MDT Small Cap Growth IS | 0.27% | 193K | $3.1M | +193,492 (0.0%) | June 30, 2026 |
| 16 | Virtus LifeSci Biotech Products ETF | 0.27% | 193K | $3.1M | — | September 30, 2026 |
| 17 | Schwab Small Cap Index | 0.24% | 175K | $2.8M | — | August 31, 2026 |
| 18 | Fidelity Total Market Index | 0.19% | 140K | $2.3M | +5,997 (+4.5%) | August 31, 2026 |
| 19 | iShares Russell 2000 Small-Cap Idx Instl | 0.19% | 135K | $2.2M | — | August 31, 2026 |
| 20 | Stt Strt SPDR® Russell2000 US SmCapETF | 0.18% | 132K | $2.1M | −9,184 (−6.5%) | September 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
OMER insider transactions
latest 1| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-01-13 | David J Borges | Sell | $12.31 | 30,000 | $369,300 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
OMER shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns OMER
Institutional investors own 51.4% of Omeros's shares and insiders 4.08%. The largest holder is BlackRock Inc with 8.35% of the shares (6.0M), as of June 30, 2026. Among the top 20 institutions, 16 added shares and 4 reduced their stake in the latest filings. Short interest is 16.30% of the float, or 7.54 days of average trading volume. The share count rose 86.2% since 2014.
Related: OMER analyst forecast, OMER key metrics. See the OMER stock overview for the latest quote and news.
OMER ownership FAQ
Who owns the most Omeros stock?
The largest shareholders of Omeros are BlackRock Inc (8.35%), Ingalls & Snyder LLC (5.06%), UBS Group AG (4.35%), Vanguard Capital Management, LLC (4.24%), State Street Corp (3.20%).
What percentage of Omeros is owned by institutions?
Institutions hold 51.4% of Omeros's shares outstanding; insiders hold 4.08%.
Which funds own Omeros?
The largest fund holders of Omeros are Vanguard MStar Total Stk Mkt Idx Invest (3.00%), iShares Russell 2000 ETF (2.58%), Fidelity Small Cap Index (1.09%), State Street® SPDR® S&P® PhrmctlsETF (0.74%), iShares Russell 2000 Value ETF (0.58%).
What is Omeros's short interest?
11.4M shares of Omeros were sold short, 16.30% of the float; at the average daily volume it would take 7.54 days to cover.
Are insiders buying or selling Omeros?
Of the latest 1 reported insider transactions in Omeros (since January 13, 2026), 0 were purchases and 1 were sales.
How many shares of Omeros are outstanding?
Omeros has 72.4M shares outstanding, of which 69.3M are in the public float.