SPRO Institutional Ownership
Who owns Spero Therapeutics, Inc. and what the big funds did with it last quarter, from every SEC 13F filing. 60 funds reported holding SPRO at Jun 30, 2026, together owning 36.9% of the company.
- ▲38 buying vs 18 selling
- ▲Held by funds +0.7 pts
- ▲Funds holding +10
- ●Superinvestors: 2 added, 2 cut
- ●Put/call not meaningful
What the filings show, not a forecast. Positions can be up to 45 days old and leave out short sales.
Funds holding and ownership
8 quartersQuarter over quarter
all 13F filers| Q2 2026 | This quarter | Q1 2026 | Change |
|---|---|---|---|
| Funds holding | 60 | 50 | +20.0% |
| In funds' top 10 | 2 | 2 | 0.0% |
| 13F shares | 21.5M | 21.1M | +1.9% |
| Held by funds | 36.9% | 36.2% | +0.7 pts |
| New positions | 21 | 5 | +320.0% |
| Increased | 17 | 13 | +30.8% |
| Reduced | 6 | 9 | −33.3% |
| Sold out | 12 | 13 | −7.7% |
| Calls (shares) | 0 | 0 | – |
| Puts (shares) | 0 | 0 | – |
| Put/call ratio | – | – | – |
Buyers vs sellers
adding or new vs cutting or sold outSuperinvestors in SPRO
All superinvestors →
Who owns SPRO
share of fund held shares- Index and passive funds19.6%
- Active managers and hedge funds71.5%
- Banks and brokers8.8%
- Pensions, insurers and other0.1%
The top 10 holders own 85.0% of all SPRO shares that funds reported. Groups are our own grouping of filers by name.
Filed so far for Q3 2026
7 funds changed their position- Mackenzie Financial CorpNew+1.8M sh
- Axxcess Wealth Management, LLCSold out−33K sh
- DLK Investment Management, LLCSold out−31K sh
- Assenagon Asset Management S.A.Trimmed−20K sh
- FNY Investment Advisers, LLCAdded+13K sh
🔒 Free account: see all 7.
Top holders
Q2 2026| # | Fund | Of company | Shares | Value | Change |
|---|---|---|---|---|---|
| 1 | GSK plc | 15.78% | 9.2M | $20.3M | 0 |
| 2 | Pfizer Inc | 4.06% | 2.4M | $5.3M | 0 |
| 3 | Vanguard Capital Management LLC | 3.50% | 2M | $4.5M | +236K |
| 4 | Renaissance Technologies LLC | 1.63% | 948K | $2.1M | −241K |
| 5 | Alphabet Inc. | 1.53% | 890K | $2M | 0 |
| 6 | Susquehanna International Group, LLP | 1.30% | 759K | $1.7M | +426K |
| 7 | BlackRock, Inc. | 1.02% | 594K | $1.3M | +161K |
| 8 | Geode Capital Management, LLC | 0.97% | 566K | $1.3M | +46K |
| 9 | Raymond James Financial Inc | 0.90% | 522K | $1.2M | +522K |
| 10 | Two Sigma Investments, LP | 0.66% | 383K | $846K | −503K |
- Raymond James Financial Inc+522K sh+$1.2M
- Susquehanna International Group, LLP+426K sh+$942K
- Arrowstreet Capital, Limited Partnership+333K sh+$736K
- Goldman Sachs Group Inc+257K sh+$568K
- Dimensional Fund Advisors LP+245K sh+$542K
- Vanguard Capital Management LLC+236K sh+$522K
- BlackRock, Inc.+161K sh+$356K
- UBS Group AG+137K sh+$302K
- Anson Funds Management LP−844K sh−$2M
- Two Sigma Investments, LP−503K sh−$1.1M
- Citadel Advisors LLC−376K sh−$881K
- Renaissance Technologies LLC−241K sh−$533K
- Squarepoint Ops LLC−194K sh−$455K
- Marshall Wace, LLP−157K sh−$368K
- Ionic Capital Management LLC−93K sh−$206K
- Quadrature Capital Ltd−40K sh−$94K
SPRO institutional ownership FAQ
Who owns the most SPRO stock?
In Q2 2026 13F filings the largest holder of SPRO was GSK plc, followed by Pfizer Inc and Vanguard Capital Management LLC. Index fund managers are usually the biggest holders of large companies.
What percentage of SPRO is owned by institutions?
Funds that file 13F reports held 36.9% of SPRO's shares at Jun 30, 2026, compared with 36.2% a quarter earlier. That counts every manager with more than $100 million in US stocks.
Are hedge funds buying SPRO?
In Q2 2026, 38 funds bought SPRO (21 of them new positions) and 18 sold (12 sold out completely). Among well known investors, 2 added and 2 cut. Our fund sentiment for SPRO is bullish.
What is SPRO's institutional put/call ratio?
Too few option positions were reported for a meaningful ratio.
How current is this SPRO ownership data?
13F filings show holdings at the end of each quarter and are due within 45 days, so positions can be up to six weeks old when they appear. We add each new filing within minutes, and the "filed so far" list shows funds that have already reported the next quarter.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Fund sentiment summarises what 13F filings show and is not a forecast. Holdings come from SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.