SPRO · Insider trading · 13F holders · Congress trades
Spero Therapeutics, Inc. (SPRO)
Who is buying and selling SPRO: company insiders on SEC Form 4, hedge funds and superinvestors on Form 13F, and members of Congress under the STOCK Act. Every figure links to the filing or page it comes from.
- 13F filers holding
- 3
- Insider buys, 90 days
- $0
- Insider sales, 90 days
- $0
- Congress trades, 12 months
- 0
SPRO at a glance
- No open-market insider purchases or sales of SPRO were filed in the last 90 days.
- 3 13F filers hold SPRO among their 50 largest positions, worth $27.6M combined. The biggest bets by portfolio weight are GSK plc (3.4%), Pfizer Inc (3.1%) and Alphabet Inc. (0.0%).
- No member of Congress has disclosed a trade in SPRO.
SPRO insider trading
No open-market insider purchases or sales of SPRO were filed in the last 90 days.
Who owns SPRO? Hedge funds and superinvestors
3 13F filers hold SPRO among their 50 largest positions, worth $27.6M combined. The biggest bets by portfolio weight are GSK plc (3.4%), Pfizer Inc (3.1%) and Alphabet Inc. (0.0%).
| Manager | % of portfolio | Value | Shares | Last quarter | 13F |
|---|---|---|---|---|---|
| GSK plcCorporation | 3.4% | $20.3M | 9,190,606 | +0.0% shares | Q2 2026 |
| Pfizer IncCorporation | 3.1% | $5.3M | 2,362,348 | +0.0% shares | Q2 2026 |
| Alphabet Inc.Corporation | 0.0% | $2.0M | 889,979 | +0.0% shares | Q2 2026 |
Each manager counts with its latest 13F (Q2 2026: 3). Screen SPRO in the grand portfolio →
SPRO stock trades by members of Congress
No member of Congress has disclosed a trade in SPRO.
SPRO questions and answers
Are insiders buying SPRO stock?
No open-market insider purchases or sales of SPRO were filed in the last 90 days.
Which hedge funds own SPRO?
3 13F filers hold SPRO among their 50 largest positions, worth $27.6M combined. The biggest bets by portfolio weight are GSK plc (3.4%), Pfizer Inc (3.1%) and Alphabet Inc. (0.0%).
Has Congress traded SPRO?
No member of Congress has disclosed a trade in SPRO.
Who is the largest holder of SPRO?
Among 13F filers, GSK plc reports the largest SPRO position, $20.3M (9,190,606 shares) in its Q2 2026 13F. The biggest bet by portfolio weight is GSK plc's: 3.4% of its portfolio.
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