SPERO THERAPEUTICS INC (SPRO)
Institutional ownership reported to the SEC as of Q2 2026, across 32 quarters.
Institutions report 21,466,406 shares against 58,234,827 outstanding. Shares only - option lines are excluded, which is why this can be compared with the company at all. The count comes from the cover page of the company's own most recent report, so it is dated when that was filed rather than at quarter end.
Calls and puts are the parts of reported value carried in derivative lines rather than shares, and they point in opposite directions: a manager holding calls is positioned for the security, one holding puts against it - or hedging shares they already own, which is why index funds carry so many. Most sites add the two together and report one figure, which averages away the only interesting part.
Holders
| Filer | Value | Shares | Their book | Held | Change |
|---|---|---|---|---|---|
| GSK plc | $20.3M | 9,190,606 | 3.37% | 3q | HELD |
| Pfizer Inc | $5.3M | 2,362,348 | 3.13% | 7q | HELD |
| VANGUARD CAPITAL MANAGEMENT LLC | $4.5M | 2,036,226 | 0.00% | 2q | +13.1%+$522.3K |
| RENAISSANCE TECHNOLOGIES LLC | $2.1M | 947,904 | 0.00% | 18q | -20.3%-$533.3K |
| Alphabet Inc. | $2.0M | 889,979 | 0.00% | 35q | HELD |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | $1.8M incl. $106.7K options CALL+PUT | 759,290 | 0.00% | 5q | +127.9%+$1.0M |
| BlackRock, Inc. | $1.3M | 594,404 | 0.00% | 8q | +37.2%+$356.3K |
| GEODE CAPITAL MANAGEMENT, LLC | $1.3M | 566,329 | 0.00% | 31q | +8.9%+$102.6K |
| RAYMOND JAMES FINANCIAL INC | $1.2M | 521,705 | 0.00% | new | NEW |
| TWO SIGMA INVESTMENTS, LP | $846.0K | 382,814 | 0.00% | 4q | -56.8%-$1.1M |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | $735.9K | 332,970 | 0.00% | new | NEW |
| VANGUARD FIDUCIARY TRUST CO | $635.7K | 287,648 | 0.00% | 2q | +8.9%+$52.0K |
| GSA CAPITAL PARTNERS LLP | $632.0K | 285,906 | 0.04% | 4q | +2.7%+$16.8K |
| DIMENSIONAL FUND ADVISORS LP | $607.6K | 274,820 | 0.00% | 4q | +823.2%+$541.8K |
| GOLDMAN SACHS GROUP INC | $567.9K | 256,985 | 0.00% | new | NEW |
| JANE STREET GROUP, LLC | $512.7K incl. $163.3K options CALL+PUT | 158,097 | 0.00% | 4q | +48.7%+$167.8K |
| STATE STREET CORP | $474.6K | 214,751 | 0.00% | 31q | HELD |
| UBS Group AG | $308.7K | 139,680 | 0.00% | 29q | +4542.1%+$302.0K |
| SIMPLEX TRADING, LLC | $298.4K incl. $162.9K options CALL+PUT | 61,312 | 0.00% | 8q | +102.3%+$150.9K |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | $253.7K | 114,800 | 0.00% | 14q | HELD |
| NORTHERN TRUST CORP | $239.3K | 108,274 | 0.00% | 31q | -10.5%-$28.1K |
| Point72 Asset Management, L.P. | $230.7K | 104,377 | 0.00% | 3q | +74.9%+$98.8K |
| Ionic Capital Management LLC | $227.0K | 102,698 | 0.03% | 5q | -47.6%-$206.1K |
| Federation des caisses Desjardins du Quebec | $202.2K | 91,900 | 0.00% | new | NEW |
| Shay Capital LLC | $160.0K | 72,391 | 0.01% | 4q | +2.9%+$4.5K |
| GROUP ONE TRADING LLC | $159.5K incl. $135.5K options CALL+PUT | 10,869 | 0.00% | 5q | HELD |
| CITADEL ADVISORS LLC | $145.0K PUT | options only | 0.00% | 9q | OPTIONS |
| Invesco Ltd. | $142.0K | 64,245 | 0.00% | 5q | +41.6%+$41.7K |
| Verdad Advisers, LP | $113.5K | 51,335 | 0.11% | 2q | +53.4%+$39.5K |
| XTX Topco Ltd | $111.7K | 50,536 | 0.00% | new | NEW |
| Assenagon Asset Management S.A. | $82.4K | 37,272 | 0.00% | 4q | +100.0%+$41.2K |
| AMERICAN CENTURY COMPANIES INC | $81.4K | 36,811 | 0.00% | new | NEW |
| Capital Asset Advisory Services LLC | $71.9K | 32,548 | 0.00% | 5q | HELD |
| AXXCESS WEALTH MANAGEMENT, LLC | $71.9K | 32,548 | 0.00% | new | NEW |
| Three Seasons Wealth, LLC | $66.3K | 30,000 | 0.01% | 11q | HELD |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | $63.1K | 28,565 | 0.00% | 15q | HELD |
| Vanguard Global Advisers, LLC | $56.2K | 25,446 | 0.00% | 2q | HELD |
| Global Retirement Partners, LLC | $55.2K | 25,000 | 0.00% | new | NEW |
| OPPENHEIMER & CO INC | $50.5K | 22,850 | 0.00% | new | NEW |
| MILLENNIUM MANAGEMENT LLC | $42.6K | 19,298 | 0.00% | new | NEW |
| DLK Investment Management, LLC | $40.8K | 31,355 | 0.02% | new | NEW |
| Susquehanna Portfolio Strategies, LLC | $39.0K | 17,628 | 0.00% | new | NEW |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC | $35.6K | 16,095 | 0.00% | new | NEW |
| Qube Research & Technologies Ltd | $30.2K | 13,644 | 0.00% | new | NEW |
| SG Americas Securities, LLC | $25.0K | 11,268 | 0.00% | new | NEW |
| TWO SIGMA SECURITIES, LLC | $23.4K | 10,576 | 0.00% | new | NEW |
| PRUDENTIAL FINANCIAL INC | $23.0K | 10,400 | 0.00% | new | NEW |
| CITIGROUP INC | $21.3K | 9,625 | 0.00% | 3q | -49.7%-$21.0K |
| FNY Investment Advisers, LLC | $18.0K | 8,300 | 0.01% | 4q | +56.6%+$6.5K |
| JONES FINANCIAL COMPANIES LLLP | $17.4K | 7,678 | 0.00% | 3q | HELD |
| ROYAL BANK OF CANADA | $4.0K | 2,014 | 0.00% | new | NEW |
| MORGAN STANLEY | $2.0K | 914 | 0.00% | 35q | -79.9%-$8.0K |
| FMR LLC | $663 | 300 | 0.00% | new | NEW |
| OSAIC HOLDINGS, INC. | $640 | 290 | 0.00% | 5q | HELD |
| JPMORGAN CHASE & CO | $533 | 236 | 0.00% | 13q | HELD |
| WELLS FARGO & COMPANY/MN | $442 | 200 | 0.00% | 15q | HELD |
| Rialto Wealth Management, LLC | $381 | 172 | 0.00% | new | NEW |
| US BANCORP \DE\ | $334 | 151 | 0.00% | 15q | HELD |
| SBI Securities Co., Ltd. | $29 | 13 | 0.00% | 7q | +44.4% |
| Farther Finance Advisors, LLC | $22 | 10 | 0.00% | 3q | HELD |
| INTERNATIONAL ASSETS INVESTMENT MANAGEMENT, LLC | $0 | none filed | 0.00% | new | NEW |
What the company announced
Form 8-K filings from the last 120 days, showing only the items worth a reader's attention. Earnings releases, exhibit attachments and general disclosures are filed constantly and are left out. Filed is when the SEC received it; event is the date the company says the thing happened.
| Filed | Event date | What | Source |
|---|---|---|---|
| 2026-10-27 | 2026-10-26 | Directors or officers departed or appointed | filing |
| 2026-08-28 | 2026-08-28 | Material agreement entered | filing |
Quarter by quarter
Coverage begins with the quarter ending 2018-12-31. Earlier filings exist only as occasional late amendments, too sparse to describe a market, so they are not shown.
| Quarter | Holders | Value | Shares | New | Added | Trimmed | Options |
|---|---|---|---|---|---|---|---|
| Q3 2026 | 5 | $78.9K | 65,883 | 0 | 3 | 1 | 0.0% |
| Q2 2026 | 61 | $48.2M | 21,466,406 | 22 | 17 | 7 | 1.5% |
| Q1 2026 | 51 | $49.8M | 21,065,197 | 5 | 13 | 9 | 1.1% |
| Q4 2025 | 57 | $49.8M | 21,119,398 | 13 | 13 | 11 | 1.1% |
| Q3 2025 | 49 | $21.8M | 11,311,738 | 13 | 13 | 8 | 2.5% |
| Q2 2025 | 44 | $34.0M | 11,084,443 | 19 | 9 | 8 | 5.4% |
| Q1 2025 | 38 | $10.9M | 15,108,016 | 2 | 7 | 10 | 0.1% |
| Q4 2024 | 50 | $16.5M | 16,055,103 | 8 | 12 | 8 | 0.0% |
| Q3 2024 | 46 | $16.5M | 12,343,990 | 5 | 5 | 10 | 0.0% |
| Q2 2024 | 50 | $18.1M | 13,877,215 | 4 | 12 | 8 | 0.1% |
| Q1 2024 | 57 | $23.8M | 13,773,046 | 13 | 12 | 13 | 0.3% |
| Q4 2023 | 48 | $19.7M | 13,377,970 | 4 | 9 | 9 | 0.1% |
| Q3 2023 | 53 | $17.2M | 14,186,051 | 4 | 10 | 14 | 0.4% |
| Q2 2023 | 56 | $21.0M | 14,363,122 | 13 | 10 | 14 | 1.0% |
| Q1 2023 | 48 | $25.6M | 17,594,838 | 4 | 14 | 7 | 0.7% |
| Q4 2022 | 57 | $25.2M | 14,222,474 | 15 | 8 | 19 | 2.4% |
| Q3 2022 | 61 | $71.2M | 35,014,196 | 16 | 9 | 17 | 1.6% |
| Q2 2022 | 65 | $15.8M | 21,178,569 | 14 | 19 | 18 | 0.4% |
| Q1 2022 | 97 | $703.0M | 80,783,066 | 23 | 15 | 19 | 0.0% |
| Q4 2021 | 85 | $447.8M | 27,833,087 | 2 | 23 | 21 | 0.5% |
| Q3 2021 | 88 | $506.3M | 27,326,322 | 7 | 21 | 26 | 0.6% |
| Q2 2021 | 86 | $371.2M | 26,443,938 | 14 | 26 | 19 | 0.5% |
| Q1 2021 | 90 | $367.4M | 24,789,110 | 12 | 24 | 25 | 0.7% |
| Q4 2020 | 89 | $619.6M | 31,717,114 | 25 | 32 | 22 | 0.8% |
| Q3 2020 | 78 | $199.9M | 17,847,873 | 13 | 28 | 23 | 0.4% |
| Q2 2020 | 77 | $239.2M | 17,678,196 | 27 | 34 | 11 | 0.0% |
| Q1 2020 | 59 | $98.7M | 12,217,330 | 6 | 29 | 16 | 0.0% |
| Q4 2019 | 60 | $110.9M | 11,530,499 | 8 | 27 | 10 | 0.0% |
| Q3 2019 | 58 | $116.3M | 10,970,989 | 6 | 26 | 12 | 0.0% |
| Q2 2019 | 59 | $129.3M | 11,238,298 | 9 | 25 | 9 | 0.0% |
| Q1 2019 | 54 | $124.3M | 9,711,307 | 12 | 13 | 17 | 0.0% |
| Q4 2018 | 50 | $1.1B | 177,485,340 | 3 | 1 | 1 | 0.0% |