SPERO THERAPEUTICS INC (SPRO) Institutional Ownership Changes & 13F Activity
SPERO THERAPEUTICS INC (SPRO). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings (Q1 2026). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions in the latest reporting period. Notable filers include Vanguard Capital Management Llc, Two Sigma Investments, Lp, Vanguard Fiduciary Trust Co, Two Sigma Advisers, Lp, and Anson Funds Management Lp.
| Institution | Type | Change in shares | Change Position % | Shares | Reported stock balance | Portfolio quarter | Filing date |
|---|---|---|---|---|---|---|---|
| Two Sigma Investments, Lp | Buy | +513,061 | +137.7% | 885,631 | $2.07M | Q1 2026 | May 15, 2026 |
| Marshall Wace, Llp | Buy | +157,072 | — | 157,072 | $367.55K | Q1 2026 | May 15, 2026 |
| Intrepid Family Office Llc | Sell | -148,721 | -90.1% | 16,279 | $38.09K | Q1 2026 | May 15, 2026 |
| Omers Administration Corp | Sell | -91,727 | -70.0% | 39,400 | $92.20K | Q1 2026 | May 15, 2026 |
| Squarepoint Ops Llc | Buy | +74,867 | +62.7% | 194,301 | $454.66K | Q1 2026 | May 15, 2026 |
| Susquehanna International Group, Llp | Buy | +39,415 | +13.4% | 333,115 | $779.49K | Q1 2026 | May 15, 2026 |
| Verdad Advisers, Lp | Buy | +33,455 | — | 33,455 | $78.28K | Q1 2026 | May 15, 2026 |
| Citadel Advisors Llc | Sell | -21,406 | -5.4% | 376,458 | $880.91K | Q1 2026 | May 15, 2026 |
| Schonfeld Strategic Advisors Llc | Buy | +20,314 | — | 20,314 | $47.53K | Q1 2026 | May 15, 2026 |
| Occudo Quantitative Strategies Lp | Buy | +16,421 | — | 16,421 | $41.22K | Q1 2026 | May 15, 2026 |
| Point72 Asset Management, L.P. | Buy | +16,089 | +36.9% | 59,668 | $139.62K | Q1 2026 | May 15, 2026 |
| Shay Capital Llc | Buy | +10,065 | +16.7% | 70,354 | $164.63K | Q1 2026 | May 15, 2026 |
| Geode Capital Management, Llc | Sell | -9,273 | -1.8% | 519,922 | $1.22M | Q1 2026 | May 15, 2026 |
| State Street Corp | Buy | +4,600 | +2.2% | 214,751 | $502.52K | Q1 2026 | May 15, 2026 |
| Morgan Stanley | Buy | +4,239 | +1354.3% | 4,552 | $10.65K | Q1 2026 | May 15, 2026 |
| Quadrature Capital Ltd | Buy | +2,329 | +6.2% | 40,128 | $93.90K | Q1 2026 | May 15, 2026 |
| Jones Financial Companies Lllp | Buy | +1,201 | +18.5% | 7,678 | $17.89K | Q1 2026 | May 15, 2026 |
| Anson Funds Management Lp | Sell | -203,106 | -32.5% | 421,956 | $987.38K | Q1 2026 | May 14, 2026 |
| Renaissance Technologies LLC | Sell | -90,287 | -7.1% | 1,189,235 | $2.78M | Q1 2026 | May 14, 2026 |
| Simplex Trading, Llc | Sell | -5,382 | -15.1% | 30,304 | $70.91K | Q1 2026 | May 14, 2026 |
| Blackrock, Inc. | Sell | -414 | -0.1% | 433,202 | $1.01M | Q1 2026 | May 13, 2026 |
| Jane Street Group, Llc | Sell | -51,999 | -32.8% | 106,345 | $248.85K | Q1 2026 | May 12, 2026 |
| Citigroup Inc | Buy | +19,118 | +112458.8% | 19,135 | $44.78K | Q1 2026 | May 11, 2026 |
| Caitong International Asset Management Co., Ltd | Buy | +3 | — | 3 | $7.00 | Q1 2026 | May 11, 2026 |
| Vanguard Capital Management Llc | Buy | +1,799,880 | — | 1,799,880 | $4.21M | Q1 2026 | May 08, 2026 |
| Vanguard Fiduciary Trust Co | Buy | +264,115 | — | 264,115 | $618.03K | Q1 2026 | May 08, 2026 |
| Gsa Capital Partners Llp | Buy | +99,374 | +55.5% | 278,304 | $651.00K | Q1 2026 | May 08, 2026 |
| Vanguard Global Advisers, Llc | Buy | +25,446 | — | 25,446 | $59.54K | Q1 2026 | May 08, 2026 |
| Ubs Group Ag | Sell | -113,438 | -97.4% | 3,009 | $7.04K | Q1 2026 | May 05, 2026 |
| Two Sigma Advisers, Lp | Sell | -216,600 | -100.0% | 0 | $0.00 | Q1 2026 | Feb 17, 2026 |
Frequently asked questions about SPRO activity
Which institutional owners are buying SPRO?
Institutional owners buying SPRO include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in SPRO activity?
"Buy" means an investor increased their reported position in SPRO compared to the prior reporting period. This reflects growing exposure to SPERO THERAPEUTICS INC (SPRO) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in SPRO increasing?
Institutional interest in SPRO can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.
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