13F Insight
DOSSIER · 13F Holders · Q1 2026Cheap mega-capRe-rated
SPRO

SPERO THERAPEUTICS INC

52 institutions still hold SPERO THERAPEUTICS INC as of Q1 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 84833T103·52 13F holders·last filed Mar 31, 2026
Market cap
—
▼ 3.2%
vs prior quarter
13F value held
$48M
53.0% inst. owned
of float
Holders
52
+37 QoQ
filers reporting
Activity
+20 / −65
+881 added · −874 reduced
this quarter
Concentration
44.77%
GSK plc #1
top holder share
AI Holders Summary · Q1 2026

52 institutions reported SPRO in Q1 2026. GSK plc leads at 44.8% of the visible book. +37 net new institutions vs prior quarter — accumulation reading.

Top holders

Sorted by position value. Source: SEC EDGAR 13F-HR filings.

#HolderValueShares% port.Quarter
01
GSK plc
CIK 0001131399
$22M9.2M3.59%Q1 202602
PFIZER INC
CIK 0000078003
$6M2.4M2.31%Q1 202603
VANGUARD CAPITAL MANAGEMENT LLC
CIK 0002100119· Index
$4M1.8M0.00%Q1 202604
RENAISSANCE TECHNOLOGIES LLC
CIK 0001037389
$3M1.2M0.00%Q1 202605
Alphabet Inc.
CIK 0001652044
$2M890K0.05%Q1 202606
TWO SIGMA INVESTMENTS, LP
CIK 0001179392
$2M886K0.00%Q1 202607
Anson Funds Management LP
CIK 0001491072
$2M844K0.09%Q1 202608
GEODE CAPITAL MANAGEMENT, LLC
CIK 0001214717· Index
$1M520K0.00%Q1 202609
CITADEL ADVISORS LLC
CIK 0001423053
$1M471K0.00%Q4 202510
BlackRock, Inc.
CIK 0002012383
$1M433K0.00%Q1 202611
SUSQUEHANNA INTERNATIONAL GROUP, LLP
CIK 0001446194· Market maker
$892,979382K0.00%Q1 202612
VANGUARD FIDUCIARY TRUST CO
CIK 0000933478· Index
$618,029264K0.00%Q1 202613
TWO SIGMA ADVISERS, LP
CIK 0001478735
$504,678217K0.00%Q4 202514
STATE STREET CORP
CIK 0000093751
$502,517215K0.00%Q1 202615
Ionic Capital Management LLC
CIK 0001386462
$456,538196K0.06%Q4 202516
Squarepoint Ops LLC
CIK 0001642575
$454,664194K0.00%Q1 202617
JANE STREET GROUP, LLC
CIK 0001595888· Market maker
$427,389183K0.00%Q1 202618
NORTHERN TRUST CORP
CIK 0000073124· Index
$283,103121K0.00%Q1 202619
BRIDGEWAY CAPITAL MANAGEMENT, LLC
CIK 0001107261
$268,632115K0.01%Q1 202620
Shay Capital LLC
CIK 0001723643
$164,62870K0.01%Q1 2026
Page 1 of 3
32 more holders available. Log in →