SPRO Spero Therapeutics, Inc.

NASDAQ
$1.23

Spero Therapeutics, Inc. (SPRO) Institutional Ownership

What the institutions did with SPRO last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.

Managers compared
70
filed both this quarter and last
Managers holding
58
+8 on the quarter
Buyers
37
20 opened new
Sellers
18
12 sold out entirely
Buyer share
67.3%
of managers who traded it
Breadth
+34.6
net buyers, as a share of those trading

Every manager below opens. Subscribers can see any firm's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.

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Ownership map

Each block is one manager, sized by shares held and colored by how much they moved the position last quarter. Green added, red cut, grey stood pat.

Cut Unchanged Added Color saturates at ±50%.

Largest holders

Manager Shares % of reported
GSK plc 9.2M 42.8%
Pfizer Inc 2.4M 11.0%
VANGUARD CAPITAL MANAGEMENT LLC 2.0M 9.5%
RENAISSANCE TECHNOLOGIES LLC 947.9K 4.4%
Alphabet Inc. 890.0K 4.1%
SUSQUEHANNA INTERNATIONAL GROUP, LLP 759.3K 3.5%
BlackRock, Inc. 594.4K 2.8%
GEODE CAPITAL MANAGEMENT, LLC 566.3K 2.6%
RAYMOND JAMES FINANCIAL INC 521.7K 2.4%
TWO SIGMA INVESTMENTS, LP 382.8K 1.8%
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 333.0K 1.6%
VANGUARD FIDUCIARY TRUST CO 287.6K 1.3%
GSA CAPITAL PARTNERS LLP 285.9K 1.3%
DIMENSIONAL FUND ADVISORS LP 274.8K 1.3%
GOLDMAN SACHS GROUP INC 257.0K 1.2%
STATE STREET CORP 214.8K 1.0%
JANE STREET GROUP, LLC 158.1K 0.7%
UBS Group AG 139.7K 0.7%
BRIDGEWAY CAPITAL MANAGEMENT, LLC 114.8K 0.5%
NORTHERN TRUST CORP 108.3K 0.5%
Point72 Asset Management, L.P. 104.4K 0.5%
Ionic Capital Management LLC 102.7K 0.5%
Federation des caisses Desjardins du Quebec 91.9K 0.4%
Shay Capital LLC 72.4K 0.3%
Invesco Ltd. 64.2K 0.3%

Largest changes

Manager Action Previous Current Change
Anson Funds Management LP Sold Out 843.9K 0 -843.9K
RAYMOND JAMES FINANCIAL INC New 0 521.7K +521.7K
TWO SIGMA INVESTMENTS, LP Reduced 885.6K 382.8K -502.8K
SUSQUEHANNA INTERNATIONAL GROUP, LLP Increased 333.1K 759.3K +426.2K
CITADEL ADVISORS LLC Sold Out 376.5K 0 -376.5K
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP New 0 333.0K +333.0K
GOLDMAN SACHS GROUP INC New 0 257.0K +257.0K
DIMENSIONAL FUND ADVISORS LP Increased 29.8K 274.8K +245.1K
RENAISSANCE TECHNOLOGIES LLC Reduced 1.2M 947.9K -241.3K
VANGUARD CAPITAL MANAGEMENT LLC Increased 1.8M 2.0M +236.3K
Squarepoint Ops LLC Sold Out 194.3K 0 -194.3K
BlackRock, Inc. Increased 433.2K 594.4K +161.2K
MARSHALL WACE, LLP Sold Out 157.1K 0 -157.1K
UBS Group AG Increased 3.0K 139.7K +136.7K
Ionic Capital Management LLC Reduced 195.9K 102.7K -93.2K
Federation des caisses Desjardins du Quebec New 0 91.9K +91.9K
JANE STREET GROUP, LLC Increased 106.3K 158.1K +51.8K
XTX Topco Ltd New 0 50.5K +50.5K
GEODE CAPITAL MANAGEMENT, LLC Increased 519.9K 566.3K +46.4K
Point72 Asset Management, L.P. Increased 59.7K 104.4K +44.7K
Quadrature Capital Ltd Sold Out 40.1K 0 -40.1K
OMERS ADMINISTRATION Corp Sold Out 39.4K 0 -39.4K
AMERICAN CENTURY COMPANIES INC New 0 36.8K +36.8K
AXXCESS WEALTH MANAGEMENT, LLC New 0 32.5K +32.5K
DLK Investment Management, LLC New 0 31.4K +31.4K
SIMPLEX TRADING, LLC Increased 30.3K 61.3K +31.0K
VANGUARD FIDUCIARY TRUST CO Increased 264.1K 287.6K +23.5K
OPPENHEIMER & CO INC New 0 22.9K +22.9K
Schonfeld Strategic Advisors LLC Sold Out 20.3K 0 -20.3K
MILLENNIUM MANAGEMENT LLC New 0 19.3K +19.3K
Invesco Ltd. Increased 45.4K 64.2K +18.9K
Assenagon Asset Management S.A. Increased 18.6K 37.3K +18.6K
Verdad Advisers, LP Increased 33.5K 51.3K +17.9K
Susquehanna Portfolio Strategies, LLC New 0 17.6K +17.6K
Torrey Growth & Income Advisors Sold Out 17.0K 0 -17.0K
OCCUDO QUANTITATIVE STRATEGIES LP Sold Out 16.4K 0 -16.4K
INTREPID FAMILY OFFICE LLC Sold Out 16.3K 0 -16.3K
SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC New 0 16.1K +16.1K
Qube Research & Technologies Ltd New 0 13.6K +13.6K
NORTHERN TRUST CORP Reduced 121.0K 108.3K -12.7K
SG Americas Securities, LLC New 0 11.3K +11.3K
GROUP ONE TRADING LLC New 0 10.9K +10.9K
TWO SIGMA SECURITIES, LLC New 0 10.6K +10.6K
PRUDENTIAL FINANCIAL INC New 0 10.4K +10.4K
CITIGROUP INC Reduced 19.1K 9.6K -9.5K
GSA CAPITAL PARTNERS LLP Increased 278.3K 285.9K +7.6K
MORGAN STANLEY Reduced 4.6K 914 -3.6K
FNY Investment Advisers, LLC Increased 5.3K 8.3K +3.0K
Shay Capital LLC Increased 70.4K 72.4K +2.0K
ROYAL BANK OF CANADA New 0 2.0K +2.0K
FMR LLC New 0 300 +300
Rialto Wealth Management, LLC New 0 172 +172
BNP PARIBAS FINANCIAL MARKETS Sold Out 40 0 -40
SBI Securities Co., Ltd. Increased 9 13 +4
Caitong International Asset Management Co., Ltd Sold Out 3 0 -3

13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.