Spero Therapeutics SPRO Insider Ownership

NASDAQ SPRO
$1.17 -0.02 (-1.68%)
At close: Sep 9, 2026 · 4:00 PM EDT

Insider Holdings by Owner

9.83Mn Shares

Insider Ownership Statistics

as of 30 Jun, 2023
Insider Ownership
3.68%
-0.0031% pp QoQ
Shares Held by Insiders
1.93Mn
filed for Jun 2023
0.00% QoQ
Shares Outstanding
56.28Mn
56,280,844 shares
Direct Holdings
0
Indirect: 1.93Mn
Net Shares Traded (QoQ)
0
no net change in Jun 2023
Insiders Holding Shares
17
with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding
Latest
Average ownership
Peak ownership

Shares Purchased/Sold by Insiders

Bought Sold
Latest quarter
Net over range
Buying quarters

Insider Ownership Summary

Quarter ending 30 Jun, 2023

SPRO's three largest insider shareholders as of September 09, 2026 are Capital Management, Llc Aquilo (TenPercentOwner, 5.22Mn shares), Capital Management, Llc Aquilo (TenPercentOwner, 3.42Mn shares), Sath Shukla (Ceo President, 1.74Mn shares).

Form 4 Holdings

Insiders Holding SPRO

Insiders 17
Shares held 9.83Mn
Of outstanding 17.47%
# Insider Position Direct Indirect Total Share of Insiders Last Filed
1 Capital Management, Llc Aquilo TenPercentOwner 0 3,419,435 3,419,435 34.8% 26 Sep, 2022
2 Sath Shukla Ceo President 1,736,883 0 1,736,883 17.7% 05 Feb, 2025
3 Esther Rajavelu Cfo Cbo 1,012,091 0 1,012,091 10.3% 09 Feb, 2026
4 Kamal Hamed Chief Medical Officer 788,117 0 788,117 8.0% 05 Feb, 2024
5 Timothy Keutzer Chief Operating Officer 742,506 0 742,506 7.6% 09 Feb, 2026
6 Ankit Mahadevia Ceo And President 703,294 0 703,294 7.2% 02 Sep, 2025
7 Tamara L Joseph Chief Legal Officer 531,615 0 531,615 5.4% 05 Feb, 2024
8 Debra Zack Chief Medical Officer 162,311 0 162,311 1.7% 06 Aug, 2026
9 Milind Deshpande Director 101,454 0 101,454 1.0% 25 Jun, 2026
10 Patrick V.J.J. Vink Director 85,000 0 85,000 0.9% 25 Jun, 2026
11 John C Jr Pottage Director 85,000 0 85,000 0.9% 25 Jun, 2026
12 Cynthia Smith Director 85,000 0 85,000 0.9% 25 Jun, 2026
13 Frank E Thomas Director 85,000 0 85,000 0.9% 25 Jun, 2026
14 Kathleen Tregoning Director 85,000 0 85,000 0.9% 25 Jun, 2026
15 Scott Thomas Jackson Director 85,000 0 85,000 0.9% 25 Jun, 2026
16 Cristina Larkin Chief Operating Officer 63,581 0 63,581 0.6% 03 Feb, 2022
17 David A. Melnick Chief Medical Officer 62,081 0 62,081 0.6% 03 Feb, 2022

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

338 Insider Transactions

Source SEC Form 4
Latest quarter Jun 2023
Download Data
Date Insider Position Transaction Shares Price Value Shares Held After Ownership
03 Aug, 2026 Debra Zack Chief Medical Officer Acquired A 162,311 $0.00 $0 162,311 Direct
03 Aug, 2026 Debra Zack Chief Medical Officer Acquired A 324,675 $0.00 $0 324,675 Direct
23 Jun, 2026 Scott Thomas Jackson Director Acquired A 10,000 $0.00 $0 85,000 Direct
23 Jun, 2026 Patrick V.J.J. Vink Director Acquired A 10,000 $0.00 $0 85,000 Direct
23 Jun, 2026 Cynthia Smith Director Acquired A 10,000 $0.00 $0 85,000 Direct
23 Jun, 2026 Milind Deshpande Director Acquired A 10,000 $0.00 $0 101,454 Direct
23 Jun, 2026 Kathleen Tregoning Director Acquired A 10,000 $0.00 $0 85,000 Direct
23 Jun, 2026 Frank E Thomas Director Acquired A 10,000 $0.00 $0 85,000 Direct
23 Jun, 2026 John C Jr Pottage Director Acquired A 10,000 $0.00 $0 85,000 Direct
23 Jun, 2026 Scott Thomas Jackson Director Acquired A 20,000 $0.00 $0 20,000 Direct
23 Jun, 2026 Cynthia Smith Director Acquired A 20,000 $0.00 $0 20,000 Direct
23 Jun, 2026 Patrick V.J.J. Vink Director Acquired A 20,000 $0.00 $0 20,000 Direct
23 Jun, 2026 John C Jr Pottage Director Acquired A 20,000 $0.00 $0 20,000 Direct
23 Jun, 2026 Frank E Thomas Director Acquired A 20,000 $0.00 $0 20,000 Direct
23 Jun, 2026 Milind Deshpande Director Acquired A 20,000 $0.00 $0 20,000 Direct
23 Jun, 2026 Kathleen Tregoning Director Acquired A 20,000 $0.00 $0 20,000 Direct
06 Feb, 2026 Timothy Keutzer Chief Operating Officer Disposed S 18,652 $2.36 $44.02K 742,506 Direct
06 Feb, 2026 Esther Rajavelu Officer Disposed S 37,101 $2.36 $87.56K 1,062,907 Direct
04 May, 2026 Esther Rajavelu Officer Disposed S 25,240 $2.51 $63.35K 986,851 Direct
06 Feb, 2026 Esther Rajavelu Officer Disposed S 50,816 $2.36 $119.93K 1,012,091 Direct