Who owns Seres Therapeutics, Inc.?
Prices and market caps: Cboe delayed data, at least 15 minutes delayed. Not real-time. Fundamentals from company filings.
Institutional ownership of MCRB from SEC Form 13F filings across 38 reporting managers. All positions are from one synchronized reporting period — 2026-06-30 books, filed up to 45 days after quarter end — so every row is comparable.
As of the 2026-06-30 reporting period, 38 institutions disclosed 2.3M shares of Seres Therapeutics, Inc. worth $18.2M — about 23.8% of shares outstanding; the largest disclosed holder is Flagship Pioneering, LLC. Source: SEC Form 13F filings, parsed by EvidInvest.
38
13F holders
$18.2M
value, 2026 filers
23.8%
of shares outstanding (2.3M sh)
10
new positions (2026 filers)
Top institutional holders
ordered by shares owned · positions as of 2026-06-30 · % of fund = share of the manager's own book · % of co. = share of MCRB's shares outstanding
| # | Manager | Shares | Value | % of fund | % of co. | Δ shares QoQ |
|---|---|---|---|---|---|---|
| 1 | Flagship Pioneering, LLC | 1.2M | $9.1M | 0.6% | 11.9% | 0.0% |
| 2 | VANGUARD CAPITAL MANAGEMENT LLC | 287,776 | $2.3M | 0.0% | 3% | -2.2% |
| 3 | MARSHALL WACE, LLP | 172,245 | $1.4M | 0.0% | 1.8% | +23.4% |
| 4 | Vontobel Holding Ltd. | 122,975 | $970,273 | 0.0% | 1.3% | -11.2% |
| 5 | BlackRock, Inc. | 111,000 | $875,790 | 0.0% | 1.1% | +8.8% |
| 6 | GEODE CAPITAL MANAGEMENT, LLC | 79,974 | $631,301 | 0.0% | 0.8% | +6.9% |
| 7 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 58,328 | $460,208 | 0.0% | 0.6% | -44.6% |
| 8 | VANGUARD FIDUCIARY TRUST CO | 48,685 | $384,125 | 0.0% | 0.5% | +22.8% |
| 9 | STATE STREET CORP | 33,901 | $267,479 | 0.0% | 0.3% | 0.0% |
| 10 | Lion Point Capital, LP | 31,570 | $249,087 | 1.2% | 0.3% | 0.0% |
| 11 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 31,049 | $244,977 | 0.0% | 0.3% | -1.8% |
| 12 | Sixth Street Partners Management Company, L.P.NEW | 31,049 | $244,977 | 0.0% | 0.3% | new |
| 13 | AMERICAN CENTURY COMPANIES INC | 28,313 | $223,390 | 0.0% | 0.3% | -54.6% |
| 14 | XTX Topco LtdNEW | 20,732 | $163,575 | 0.0% | 0.2% | new |
| 15 | GOLDMAN SACHS GROUP INCNEW | 15,229 | $120,157 | 0.0% | 0.2% | new |
| 16 | NORTHERN TRUST CORP | 14,765 | $116,496 | 0.0% | 0.2% | 0.0% |
| 17 | Invesco Ltd. | 12,974 | $102,365 | 0.0% | 0.1% | -10.8% |
| 18 | MORGAN STANLEY | 12,138 | $95,769 | 0.0% | 0.1% | -44.1% |
| 19 | CITADEL ADVISORS LLCNEW | 10,504 | $82,877 | 0.0% | 0.1% | new |
| 20 | SIMPLEX TRADING, LLC | 4,598 | $36,278 | 0.0% | 0% | +49.8% |
| 21 | SBI Securities Co., Ltd. | 4,182 | $32,996 | 0.0% | 0% | +20.1% |
| 22 | Integrated Wealth Concepts LLCNEW | 4,000 | $31,560 | 0.0% | 0% | new |
| 23 | GROUP ONE TRADING LLC | 3,714 | $29,303 | 0.0% | 0% | +350.7% |
| 24 | JPMORGAN CHASE & CONEW | 3,636 | $28,325 | 0.0% | 0% | new |
| 25 | Vanguard Global Advisers, LLC | 1,975 | $15,583 | 0.0% | 0% | 0.0% |
Source: SEC Form 13F-HR filings (institutional managers over $100M in US-listed positions). 13Fs disclose long positions only, up to 45 days after quarter end; each manager's latest filed quarter is shown per row and dollar values are the manager's filed marks. Aggregates labeled "2026 filers" count only managers whose latest book is a 2026 quarter. Related: valuation · options positioning · supply chain. Research, not investment advice.