Spero Therapeutics, Inc.
SPRO- Exchange
- Nasdaq
- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001701108
In the last 90 days, Spero Therapeutics, Inc. insiders filed 0 open-market purchases and 1 sale; 59 institutions reported holding it in 13F filings for Q2 2026, worth $47.5M in total; no superinvestor holds it.
Key figures
- Market capClose on Nov 11, 2026
- $59.4M
- Insider buysOpen market, last 90 days
- 0
- Insider sellsLast 90 days, $42.5K in total
- 1
- 13F holdersQ2 2026, +9 vs. previous quarter
- 59
- 13F valueReported value at the end of Q2 2026
- $47.5M
- Superinvestors holdingAt the end of Q2 2026
- 0
Price chart
Financials
See financial statementsFrom SEC filings, in USD.
- Revenue, FY2025
- $66.8M
- +39.2% year over year
- Net income, FY2025
- $8.57M
- No comparable prior period
- Free cash flow, FY2025
- –
- No comparable prior period
- Revenue, Q3 FY2026
- $0
- −100.0% year over year
Revenue flow, FY2025
Green is profit; orange is costs, expenses and taxes. Percentages are shares of revenue.
Short interest
See short dataFrom FINRA, settlement date Oct 30, 2026.
- Short interest
- 787.0K
- Shares sold short
- Change
- −53.5K
- −6.4% vs. previous
- Days to cover
- 2.23
- At average daily volume
Superinvestors holding SPRO, Q2 2026
Go to the superinvestors tabNo superinvestor reported holding SPRO at the end of Q2 2026.
Latest insider trades
See all insider tradesOpen-market purchases and sales by Spero Therapeutics, Inc. insiders from Form 4, newest first.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Nov 10, 2026 (view filing)6:29 PM ET | Nov 9 | 1 day | Rajavelu EstherSee Remarks | SSale | −40.9K | $1.04 | −$42.5K | −4.1%946.0K after | |
| May 6, 2026 (view filing) | May 4 | 2 days | Rajavelu EstherSee Remarks | SSale | −25.2K | $2.51 | −$63.4K | −2.5%986.9K after | |
| Feb 9, 2026 (view filing) | Feb 6 | 3 days | Rajavelu EstherSee Remarks | SSale | −87.9K | $2.36 | −$207.5K | −8.0%1.01M after | 2 lots |
| Feb 9, 2026 (view filing) | Feb 6 | 3 days | Keutzer TimothyChief Operating Officer | SSale | −18.7K | $2.36 | −$44.0K | −2.5%742.5K after | |
| Feb 5, 2026 (view filing) | Feb 2-4 | 3 daysLate | Keutzer TimothyChief Operating Officer | SSale | −46.6K | $2.17 | −$101.2K | −5.8%761.2K after | 3 lots |
| Feb 4, 2026 (view filing) | Feb 2 | 2 days | Rajavelu EstherSee Remarks | SSale | −18.4K | $2.20 | −$40.6K | −1.6%1.10M after | |
| Nov 12, 2025 (view filing) | Nov 7 | 5 days | Rajavelu EstherSee Remarks | SSale | −40.3K | $2.37 | −$95.4K | −4.4%869.5K after | |
| Sep 3, 2025 (view filing) | Aug 28 | 6 daysLate | Mahadevia AnkitDirector | SSale | −6.57K | $1.97 | −$12.9K | −0.9%703.3K after | |
| Sep 3, 2025 (view filing) | Aug 28 | 6 daysLate | Keutzer TimothyChief Operating Officer | SSale | −1.70K | $1.97 | −$3.34K | −0.2%739.7K after | |
| Feb 5, 2025 (view filing) | Feb 5 | Same day | Keutzer TimothyChief Operating Officer | SSale | −56.5K | $0.78 | −$44.1K | −7.1%741.4K after | 3 lots |
Top 10 13F holders, Q2 2026
See all 59 holdersThe largest institutional positions in Spero Therapeutics, Inc. at the end of Q2 2026; share changes are against Q1 2026.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| GSK plc | 9,190,606 | $20.3M | 3.37% | 00.0% | Unchanged |
| Pfizer Inc | 2,362,348 | $5.34M | 3.13% | 00.0% | Unchanged |
| Vanguard Capital Management LLC | 2,036,226 | $4.50M | 0.00% | +236,346+13.1% | Added |
| Renaissance Technologies LLC | 947,904 | $2.09M | 0.00% | −241,331−20.3% | Reduced |
| Alphabet Inc. | 889,979 | $1.97M | 0.00% | 00.0% | Unchanged |
| Susquehanna International Group, LLP | 759,290 | $1.68M | 0.00% | +426,175+127.9% | Added |
| BlackRock, Inc. | 594,404 | $1.31M | 0.00% | +161,202+37.2% | Added |
| Geode Capital Management, LLC | 566,329 | $1.25M | 0.00% | +46,407+8.9% | Added |
| Raymond James Financial Inc | 521,705 | $1.15M | 0.00% | +521,705 | New |
| Two Sigma Investments, LP | 382,814 | $846.0K | 0.00% | −502,817−56.8% | Reduced |
Holders of 5% or more of SPRO
See all 1 holders and filingsHolders whose latest Schedule 13D or 13G filing reports 5% or more of Spero Therapeutics, Inc..