SPRO insider trading — Spero Therapeutics, Inc.
No open-market insider purchases or sales were filed for Spero Therapeutics, Inc. (SPRO) in the last 90 days. Other insider transactions — such as stock awards, option exercises or tax withholding — are listed below.
Updated Oct 16, 2026.
Recent SPRO insider transactions
Every Form 4 filed by Spero Therapeutics, Inc. officers, directors and 10% owners in the last 90 days, newest first. P = open-market purchase, S = open-market sale; other codes are awards, option exercises, tax withholding or gifts.
| Trade date | Insider | Role | Type | Ownership | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|---|
| Aug 3, 2026 | Zack Debra | Chief Medical Officer | A · Grant/award · 10b5-1 | Direct | 162,311 | — | — | Form 4 |
SPRO insider trading FAQ
Are insiders buying SPRO stock?
Not on the open market. In the last 90 days, Spero Therapeutics, Inc. insiders made no open-market purchases, and no open-market sales. Purchases with the insider's own money are generally seen as a stronger signal than sales, which happen for many reasons (taxes, diversification, planned 10b5-1 sales).
Who are the insiders trading SPRO?
No insider bought or sold on the open market in the last 90 days.
Where does SPRO insider trading data come from?
Every transaction comes from SEC Form 4 filings on EDGAR. Company officers, directors and 10% owners must file a Form 4 within two business days of buying or selling. InsiderBolt reads these filings directly from the SEC.
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Insider trading data is for informational purposes only and is not investment advice. Filings can be amended; always confirm details on SEC EDGAR.