13F

Stock

Spero Therapeutics, Inc.

SPRO · held by 50 managers

Reported value

$47.6M

Holders

50

+5 new · −12 exited

Holders’ est. mark

$158K

Price effect on 42 books still in the name

Largest holder

$21.5M

GSK plc

Notable conviction

Share of each notable manager’s 13F book.

Holder count by quarter

Who holds it

Notable only
InvestorSharesValueEst. markChange
GSK plc9.19M$21.5M$91.9KAdded$91.9K
Pfizer Inc2.36M$5.5M$0Held
VANGUARD CAPITAL MANAGEMENT LLC1.8M$4.21MHeld
Renaissance Technologies1.19M$2.78M$11.9KCut−$198.5K
Alphabet Inc.890K$2.08M$8.9KAdded$8.9K
TWO SIGMA INVESTMENTS, LP885.6K$2.07M$3.73KAdded$1.2M
GEODE CAPITAL MANAGEMENT, LLC519.9K$1.22M$5.48KCut−$16.1K
BlackRock, Inc.433.2K$1.01M$4.33KAdded$3.37K
Anson Funds Management LP422K$987.4K$4.22KCut−$469K
Citadel376.5K$880.9K$3.76KCut−$46.1K
SUSQUEHANNA INTERNATIONAL GROUP, LLP333.1K$779.5K$2.94KAdded$95.2K
VANGUARD FIDUCIARY TRUST CO264.1K$618KHeld
State Street214.8K$502.5K$2.1KAdded$12.9K
Ionic Capital Management LLC195.9K$458.5K$1.96KAdded$1.96K
Squarepoint Ops LLC194.3K$454.7K$1.19KAdded$176.4K
MARSHALL WACE, LLP157.1K$367.5KNew
NORTHERN TRUST CORP121K$283.1K$1.21KAdded$1.21K
BRIDGEWAY CAPITAL MANAGEMENT, LLC114.8K$268.6K$1.15KAdded$1.15K
JANE STREET GROUP, LLC106.3K$248.8K$1.06KCut−$120.1K
Shay Capital LLC70.4K$164.6K$603Added$24.2K
Point72 Asset Management, L.P.59.7K$139.6K$436Added$38.1K
Invesco Ltd.45.4K$106.2K$247Added$48.6K
Quadrature Capital Ltd40.1K$93.9K$378Added$5.83K
Capital Asset Advisory Services LLC32.5K$92.4K$10.7KAdded$10.7K
OMERS ADMINISTRATION Corp39.4K$92.2K$394Cut−$213.3K
Verdad Advisers, LP33.5K$78.3KNew
SIMPLEX TRADING, LLC30.3K$70.9K$303Cut−$12.2K
Three Seasons Wealth, LLC30K$70.2K$300Added$300
DIMENSIONAL FUND ADVISORS LP29.8K$69.2K$158Added$158
CHARLES SCHWAB INVESTMENT MANAGEMENT INC28.6K$66.8K$286Added$286
Vanguard Global Advisers, LLC25.4K$59.5KHeld
Schonfeld Strategic Advisors LLC20.3K$47.5KNew
CITIGROUP INC19.1K$44.8K−$0Added$44.7K
Assenagon Asset Management S.A.18.6K$43.6K$186Added$186
OCCUDO QUANTITATIVE STRATEGIES LP16.4K$41.2KNew
INTREPID FAMILY OFFICE LLC16.3K$38.1K$163Cut−$346.4K
Torrey Growth & Income Advisors17K$37.6K−$2.04KCut−$2.04K
JONES FINANCIAL COMPANIES LLLP7.68K$17.9K$1Added$2.8K
MORGAN STANLEY4.55K$10.7K$3Added$9.92K
UBS Group AG3.01K$7.04K$30Cut−$264.3K
OSAIC HOLDINGS, INC.290$678$3Added$3
GSA CAPITAL PARTNERS LLP278.3K$651$2Added$234
JPMORGAN CHASE & CO236$529−$21Cut−$12K
WELLS FARGO & COMPANY/MN200$468$2Added$2
US BANCORP \DE\151$353$1Added$1
BNP PARIBAS FINANCIAL MARKETS40$94$1Added$1
Farther Finance Advisors, LLC10$25$2Added$2
SBI Securities Co., Ltd.9$21$0Held
FNY Investment Advisers, LLC5.3K$12$0Held
Caitong International Asset Management Co., Ltd3$7New

Who left

Positions as of Q1 2026. 13F filings arrive up to 45 days after quarter-end and omit shorts. Values are quarter-end marks, as filed. Estimated mark is the price effect on shares still held — not realized P&L or investment advice.