SPRO
Spero Therapeutics, Inc.
Pharmaceutical PreparationsNasdaqNon-accelerated filer<br>Smaller reporting company
Total Trades
46
Buys
10
Sells
27
Largest Trade
N/A
Insiders
7
Institutional Funds
33
Inst. Value
$1M+
Activist Filings
14
Insider Trades
| Insider | Title | Type | Value | Shares | Price | Date |
|---|---|---|---|---|---|---|
| Rajavelu Esther | See Remarks | SELL | $100K–$500K | 88K | $2.36 | Feb 10, 2026 |
| Keutzer Timothy | COO | SELL | $15K–$50K | 19K | $2.36 | Feb 10, 2026 |
| Keutzer Timothy | COO | SELL | $100K–$500K | 47K | $2.17 | Feb 5, 2026 |
| Keutzer Timothy | COO | GRANT | N/A | 68K | — | Feb 5, 2026 |
| Rajavelu Esther | See Remarks | SELL | $15K–$50K | 18K | $2.20 | Feb 5, 2026 |
| Rajavelu Esther | See Remarks | GRANT | N/A | 249K | — | Feb 5, 2026 |
| Rajavelu Esther | See Remarks | SELL | $50K–$100K | 40K | $2.37 | Nov 13, 2025 |
| Mahadevia Ankit | Director | SELL | $1K–$15K | 7K | $1.97 | Sep 3, 2025 |
| Keutzer Timothy | COO | SELL | $1K–$15K | 2K | $1.97 | Sep 3, 2025 |
| Rajavelu Esther | CFO & CBO | SELL | $50K–$100K | 41K | $1.31 | Nov 12, 2024 |
| Mahadevia Ankit | Director | SELL | $1K–$15K | 6K | $1.35 | Aug 29, 2024 |
| Keutzer Timothy | COO | SELL | $1K–$15K | 2K | $1.35 | Aug 29, 2024 |
| Shukla Sath | CEO & President | SELL | $1K–$15K | 3K | $1.35 | Aug 29, 2024 |
| Keutzer Timothy | COO | SELL | $15K–$50K | 31K | $1.36 | Feb 6, 2024 |
| Keutzer Timothy | COO | GRANT | N/A | 240K | — | Feb 6, 2024 |
| Mahadevia Ankit | Director | SELL | $50K–$100K | 64K | $1.37 | Feb 6, 2024 |
| JOSEPH TAMARA L | Chief Legal Officer | SELL | $15K–$50K | 31K | $1.37 | Feb 6, 2024 |
| JOSEPH TAMARA L | Chief Legal Officer | GRANT | N/A | 240K | — | Feb 6, 2024 |
| HAMED KAMAL | Chief Medical Offi… | SELL | $15K–$50K | 28K | $1.37 | Feb 6, 2024 |
| HAMED KAMAL | Chief Medical Offi… | GRANT | N/A | 240K | — | Feb 6, 2024 |
| Shukla Sath | CEO and President | GRANT | N/A | 680K | — | Feb 6, 2024 |
| Shukla Sath | CEO and President | SELL | $100K–$500K | 76K | $1.42 | Feb 6, 2024 |
| HAMED KAMAL | Chief Medical Offi… | SELL | $50K–$100K | 39K | $1.27 | Sep 15, 2023 |
| Keutzer Timothy | Chief Development … | SELL | $1K–$15K | 2K | $1.26 | Aug 30, 2023 |
| JOSEPH TAMARA L | Chief Legal Officer | SELL | $1K–$15K | 2K | $1.26 | Aug 30, 2023 |
| Mahadevia Ankit | Director | SELL | $1K–$15K | 9K | $1.26 | Aug 30, 2023 |
| Shukla Sath | CEO and President | SELL | $1K–$15K | 6K | $1.29 | Aug 30, 2023 |
| Mahadevia Ankit | CEO and President | SELL | $15K–$50K | 12K | $1.81 | Feb 6, 2023 |
| Keutzer Timothy | COO | SELL | $1K–$15K | 3K | $1.86 | Feb 4, 2023 |
| Keutzer Timothy | COO | GRANT | N/A | 266K | — | Feb 4, 2023 |
| JOSEPH TAMARA L | Chief Legal Officer | SELL | $1K–$15K | 3K | $1.86 | Feb 4, 2023 |
| JOSEPH TAMARA L | Chief Legal Officer | GRANT | N/A | 266K | — | Feb 4, 2023 |
| Shukla Sath | CFO | SELL | $15K–$50K | 10K | $1.83 | Feb 4, 2023 |
| Shukla Sath | CFO | GRANT | N/A | 266K | — | Feb 4, 2023 |
| Aquilo Capital Management, LLC | 10% Owner | SELL | $1M+ | 1.9M | $2.25 | Sep 26, 2022 |
| Shukla Sath | CFO | SELL | $1K–$15K | 6K | $0.89 | Aug 30, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $100K–$500K | 40K | $5.24 | Apr 28, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $100K–$500K | 50K | $8.79 | Mar 31, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $100K–$500K | 24K | $7.63 | Mar 16, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $100K–$500K | 45K | $9.53 | Mar 2, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $100K–$500K | 15K | $9.24 | Feb 23, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $1M+ | 125K | $11.59 | Feb 2, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $15K–$50K | 2K | $10.89 | Jan 26, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $500K+ | 48K | $12.41 | Jan 20, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $100K–$500K | 9K | $12.93 | Jan 12, 2022 |
| Aquilo Capital Management, LLC | 10% Owner | BUY | $1M+ | 250K | $15.42 | Jan 3, 2022 |
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Institutional Ownership
13F filings as of Dec 31, 2025 · 33 funds holding
| Fund | Shares | Value | Type |
|---|---|---|---|
| GSK plc | 9.2M | $1M+ | SH |
| PFIZER INC | 2.4M | $1M+ | SH |
| VANGUARD GROUP INC | 1.8M | $1M+ | SH |
| RENAISSANCE TECHNOLOGIES LLC | 1.3M | $1M+ | SH |
| Alphabet Inc. | 890K | $1M+ | SH |
| GEODE CAPITAL MANAGEMENT, LLC | 436K | $1M+ | SH |
| Informed Momentum Co LLC | 218K | $500K+ | SH |
| STATE STREET CORP | 210K | $100K–$500K | SH |
| GSA CAPITAL PARTNERS LLP | 179K | $100K–$500K | SH |
| OMERS ADMINISTRATION Corp | 131K | $100K–$500K | SH |
| Squarepoint Ops LLC | 119K | $100K–$500K | SH |
| ADAR1 Capital Management, LLC | 114K | $100K–$500K | SH |
| ADAR1 Capital Management, LLC | 114K | $100K–$500K | SH |
| UBS Group AG | 105K | $100K–$500K | SH |
| JANE STREET GROUP, LLC | 64K | $100K–$500K | SH |
| Point72 Asset Management, L.P. | 44K | $100K–$500K | SH |
| SIMPLEX TRADING, LLC | 36K | $50K–$100K | SH |
| Capital Asset Advisory Services LLC | 33K | $50K–$100K | SH |
| AXXCESS WEALTH MANAGEMENT, LLC | 33K | $50K–$100K | SH |
| Three Seasons Wealth, LLC | 30K | $50K–$100K | SH |
Activist & 5%+ Owners
SC 13D/13G filings — investors holding 5%+ of outstanding shares
SC 13G/A · Aug 15, 2025
2.9%
1.6M shares
SC 13D/A · Mar 28, 2025
16.4%
9.2M shares
SC 13G/A · Nov 14, 2024
6.9%
3.8M shares
SC 13G · Feb 14, 2024
8.1%
4.3M shares
Biotechnology Value Fund, L.P.
SC 13G/A · Feb 14, 2023
0.0%
0 shares
SC 13G/A · Feb 14, 2023
0.0%
0 shares
SC 13D/A · Jan 20, 2023
17.8%
9.2M shares
SC 13D/A · Nov 14, 2022
20.0%
9.2M shares
SC 13G/A · Oct 3, 2022
3.6%
1.2M shares
SC 13G · Jul 8, 2022
2.1%
691K shares
SC 13G/A · Mar 8, 2022
5.1%
1.6M shares
SC 13G/A · Feb 14, 2022
10.5%
3.4M shares
Biotechnology Value Fund, L.P.
SC 13G/A · Feb 14, 2022
6.4%
2.2M shares
Atlas Venture Fund IX, L.P. 2. (a) ¨
SC 13G/A · Jan 25, 2022
4.3%
1.4M shares