Company profile
Spero Therapeutics, Inc. Insider Trading
SPROEvery SEC Form 4 insider trading filing for Spero Therapeutics, Inc. (SPRO) since April 2023: open-market buys and sells by directors and officers, option exercises, and cluster activity, updated as each filing is reported to the SEC. Why 2023?
- Exchange
- Nasdaq
- Sector
- Pharmaceutical Preparations
- CIK
- 0001701108
- Filings
- 65
- Insiders
- 14
- Last filing
- 2026-08-03
Activity summary
No insider transactions in the last 30 days. The most recent was on August 3, 2026, when Debra Zack bought 162,311 shares. 65 filings from 14 insiders are on record below.
Three year balance
Buy and sell value by quarter, Q4 23 to Q3 26. Spero Therapeutics, Inc. insiders are net sellers across the period shown.
Bars below the rule are sales, above are purchases. Largest quarter on the chart is $393K.
90 day insight
Over the last 90 days, Spero Therapeutics, Inc. insiders bought $0 across 2 transactions with no open-market sales.
- Most active insider: Debra Zack with 2 transactions totaling $0.
Activity skews bullish: buys outpace sales.
Insider Transactions
Sourced from SEC EDGAR Form 4 filings. Updated hourly.
| Date | Insider | Company | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 3, 2026 | Debra Zack | SPRO | Award | 162,311 | — | — |
| Aug 3, 2026 | Debra Zack | SPRO | Award | 324,675 | — | — |
| Jun 23, 2026 | John C Pottage Jr | SPRO | Award | 10,000 | — | — |
| Jun 23, 2026 | John C Pottage Jr | SPRO | Award | 20,000 | — | — |
| Jun 23, 2026 | Scott Thomas Jackson | SPRO | Award | 10,000 | — | — |
45 more transactions hidden
Free account · No credit card required
Building something? Get API access →
Query this yourself
The same rows, over the API.
curl "https://api.form4api.com/v1/transactions?ticker=SPRO" \
-H "X-Api-Key: $KEY"Top insiders
By total value filed.
Institutional Ownership
Top 13F-HR holders of Spero Therapeutics, Inc. as of 2026-06-30
Data source: quarterly 13F-HR filings: institutional holders report positions within 45 days of quarter end. Joined with insider activity above: see who's loading up institutionally while insiders are trading. Full 13F-HR API →