SPRO
SPERO THERAPETCS (SPRO)
NASDAQ
$2.88+$0.08 (+3.00%)
Price as of Jun 03, 2026 7:57 PM EDT
  • $163.9M
    Market Cap
  • 7.20%
    1-Year Change
  • Biotechnology
    Industry

Top Holders

Institutional
Mutual Funds
Holder
Ownership %
Shares Held
Change (Shares, %)
Report Date
GSK PLC
15.87%
9.2M
0 (0.00%)
Mar 31, 2026
PFIZER INC
4.08%
2.4M
0 (0.00%)
Mar 31, 2026
VANGUARD GROUP INC
3.60%
2.1M
+93,607 (+4.49%)
Dec 31, 2025
N/A
3.11%
1.8M
+1.8M (+100.00%)
Mar 31, 2026
ATLAS VENTURE ASSOCIATES XI, LLC
2.38%
1.4M
+1.4M (+100.00%)
Dec 31, 2020
ATLAS VENTURE ASSOCIATES IX, LLC
2.34%
1.4M
0 (0.00%)
Sep 30, 2023
RENAISSANCE TECHNOLOGIES LLC
2.05%
1.2M
-90,287 (-7.59%)
Mar 31, 2026

Current Ownership Distribution

  • Mutual Funds321.5M (49.84%)
  • Institutions296.4M (45.95%)
  • Insiders27.2M (4.21%)
  • Other0 (0.00%)

Insider Transactions

  • 4.21% (27.2M)
    Current InsiderOwnership (%, shares)
  • 0
    Number of InsiderBuying (last 12 months)
  • $0.00
    Amount of InsiderBuying (last 12 months)
  • 3
    Number of InsiderSelling (last 12 months)
  • $19.0M
    Amount of InsiderSelling (last 12 months)
Insider Name & Title
Type
Date
Transaction Value
Shares
Share Price
Shares After Transactions
Rajavelu Esther
See Remarks
Sell
May 04, 2026
$63,352.40
25,240
$2.51
986,851
Keutzer Timothy
Chief Operating Officer
Sell
Feb 06, 2026
$44,018.72
18,652
$2.36
742,506
Rajavelu Esther
See Remarks
Sell
Feb 06, 2026
$87,558.36
37,101
$2.36
1.1M
Rajavelu Esther
See Remarks
Sell
Feb 06, 2026
$119,925.76
50,816
$2.36
1.0M
Keutzer Timothy
Chief Operating Officer
Sell
Feb 04, 2026
$7,775.04
3,471
$2.24
761,158
Keutzer Timothy
Chief Operating Officer
Sell
Feb 03, 2026
$51,839.36
24,224
$2.14
764,629
Rajavelu Esther
See Remarks
Award
Feb 02, 2026
$0.00
498,000
$0.00
498,000
Keutzer Timothy
Chief Operating Officer
Award
Feb 02, 2026
$0.00
137,000
$0.00
137,000
Rajavelu Esther
See Remarks
Award
Feb 02, 2026
$0.00
249,000
$0.00
1.1M
Keutzer Timothy
Chief Operating Officer
Award
Feb 02, 2026
$0.00
68,000
$0.00
807,744
Rajavelu Esther
See Remarks
Sell
Feb 02, 2026
$40,572.40
18,442
$2.20
1.1M
Keutzer Timothy
Chief Operating Officer
Sell
Feb 02, 2026
$41,560.20
18,891
$2.20
788,853
Mahadevia Ankit
Sell
Aug 28, 2025
$12,946.84
6,572
$1.97
703,294
Keutzer Timothy
Chief Operating Officer
Sell
Aug 28, 2025
$3,339.15
1,695
$1.97
739,744
THOMAS FRANK E
Award
Jun 12, 2025
$0.00
20,000
$0.00
75,000
Tregoning Kathleen
Award
Jun 12, 2025
$0.00
20,000
$0.00
75,000
Pottage John C Jr
Award
Jun 12, 2025
$0.00
20,000
$0.00
75,000
Deshpande Milind
Award
Jun 12, 2025
$0.00
20,000
$0.00
91,454
VINK PATRICK V.J.J.
Award
Jun 12, 2025
$0.00
20,000
$0.00
75,000
Smith Cynthia
Award
Jun 12, 2025
$0.00
20,000
$0.00
75,000
Mahadevia Ankit
Award
Jun 12, 2025
$0.00
20,000
$0.00
709,866
Rajavelu Esther
See Remarks
Award
May 02, 2025
$0.00
185,000
$0.00
909,720
Keutzer Timothy
Chief Operating Officer
Sell
Feb 05, 2025
$3,099.72
3,974
$0.78
794,002
Shukla Sath
CEO & President
Sell
Feb 05, 2025
$4,788.42
6,139
$0.78
1.9M
Mahadevia Ankit
Sell
Feb 05, 2025
$10,888.02
13,959
$0.78
745,126
Rajavelu Esther
CFO & CBO
Sell
Feb 05, 2025
$16,137.42
20,689
$0.78
724,720
Keutzer Timothy
Chief Operating Officer
Sell
Feb 05, 2025
$21,561.54
27,643
$0.78
766,359
Shukla Sath
CEO & President
Sell
Feb 05, 2025
$33,373.08
42,786
$0.78
1.8M
Mahadevia Ankit
Sell
Feb 05, 2025
$43,102.80
55,260
$0.78
689,866
Shukla Sath
CEO & President
Sell
Feb 05, 2025
$82,998.24
106,408
$0.78
1.7M