// company-profile
Seres Therapeutics, Inc.
MCRBExchangeNasdaqSectorPharmaceutical PreparationsInc.DEFilings110Insiders20
// api This Seres Therapeutics, Inc. insider-trading data is served live by the Form4API insider trading API. Get the same data via API.
// activity-summary
No insider transactions in the last 30 days.
// 90-day insight
Over the last 90 days, Seres Therapeutics, Inc. insiders bought $0 (12 transactions) and sold $444 (1 transaction).
- Most active insider: Shaff Eric D. with 4 transactions totaling $2K.
- Largest single sale: $2K by Shaff Eric D. on May 18, 2026.
- 75% of recent sales were pre-scheduled 10b5-1 trades — typically less informative than open-market activity.
Activity skews bullish — buys outpace sales.
Institutional Ownership
Top 13F-HR holders of Seres Therapeutics, Inc. as of 2026-03-31
Total reported AUM
$21.7M
QoQ change
-44.8%
Reporting period
2026-03-31
#1
Flagship Pioneering, LLC
CIK 1400240
$6.5M
733K shares
#2
Flagship Pioneering, LLC
CIK 1400240
$3.7M
423K shares
#3
VANGUARD CAPITAL MANAGEMENT LLC
CIK 2100119
$2.6M
294K shares
Data source: SEC Form 13F-HR filings. Joined with insider activity above — see who's loading up institutionally while insiders are trading. Full 13F-HR API →
Insider Transactions
Sourced from SEC EDGAR Form 4 filings. Updated hourly.
| Date | Insider | Company | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| May 18, 2026 | Brady Kelly | MCRB | Sale | 59 | $7.53 | $0K |
| May 18, 2026 | DesRosier Thomas | MCRB | Sale10b5 | 79 | $7.53 | $1K |
| May 18, 2026 | Shaff Eric D. | MCRB | Sale10b5 | 259 | $7.53 | $2K |
| May 18, 2026 | Henn Matthew R. | MCRB | Sale10b5 | 77 | $7.53 | $1K |
| May 15, 2026 | Shaff Eric D. | MCRB | Option Exercise | 391 | $0.00 | $0K |
45 more transactions hidden
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