Who owns Mereo BioPharma Group plc?
Prices and market caps: Cboe delayed data, at least 15 minutes delayed. Not real-time. Fundamentals from company filings.
Institutional ownership of MREO from SEC Form 13F filings across 60 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, 60 institutions disclosed 56.6M shares of Mereo BioPharma Group plc worth $18.0M — about 35.2% of shares outstanding; the largest disclosed holder is Rubric Capital Management LP. Source: SEC Form 13F filings, parsed by EvidInvest.
60
13F holders
$18.0M
value, 2026 filers
35.2%
of shares outstanding (56.6M sh)
14
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 MREO's shares outstanding
| # | Manager | Shares | Value | % of fund | % of co. | Δ shares QoQ |
|---|---|---|---|---|---|---|
| 1 | Rubric Capital Management LP | 15.3M | $4.9M | 0.0% | 9.5% | 0.0% |
| 2 | 683 Capital Management, LLC | 11.8M | $3.7M | 0.2% | 7.3% | -1.9% |
| 3 | BANK OF AMERICA CORP /DE/ | 8.2M | $2.6M | 0.0% | 5.1% | 0.0% |
| 4 | Defilade Capital Management, L.P. | 7.6M | $2.4M | 0.3% | 4.7% | 0.0% |
| 5 | Newtyn Management, LLC | 3.0M | $953,100 | 0.1% | 1.9% | -57.6% |
| 6 | Tejara Capital Ltd | 2.0M | $647,320 | 0.3% | 1.3% | 0.0% |
| 7 | UBS Group AG | 1.4M | $460,346 | 0.0% | 0.9% | -2.9% |
| 8 | TWO SIGMA INVESTMENTS, LP | 1.3M | $419,123 | 0.0% | 0.8% | +602.3% |
| 9 | EcoR1 Capital, LLC | 1.0M | $317,700 | 0.0% | 0.6% | -92.5% |
| 10 | JANE STREET GROUP, LLC | 774,944 | $246,200 | 0.0% | 0.5% | +453.6% |
| 11 | Ishara Investments LPNEW | 768,750 | $244,232 | 0.2% | 0.5% | new |
| 12 | Wealthspire Advisors, LLC | 765,000 | $243,041 | 0.0% | 0.5% | -3.9% |
| 13 | CITADEL ADVISORS LLCNEW | 444,158 | $141,109 | 0.0% | 0.3% | new |
| 14 | Rangeley Capital, LLC | 329,200 | $104,587 | 0.1% | 0.2% | 0.0% |
| 15 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 213,270 | $67,756 | 0.0% | 0.1% | +8.9% |
| 16 | MARSHALL WACE, LLP | 179,884 | $57,563 | 0.0% | 0.1% | -73.8% |
| 17 | XTX Topco Ltd | 174,481 | $55,433 | 0.0% | 0.1% | +106.6% |
| 18 | GROUP ONE TRADING LLC | 167,515 | $53,220 | 0.0% | 0.1% | -50.1% |
| 19 | STATE STREET CORP | 134,772 | $42,817 | 0.0% | 0.1% | +1.0% |
| 20 | NOMURA HOLDINGS INCNEW | 104,361 | $33,155 | 0.0% | 0.1% | new |
| 21 | James J. Burns & Company, LLCNEW | 95,400 | $30,309 | 0.0% | 0.1% | new |
| 22 | Quarry LPNEW | 93,750 | $29,784 | 0.0% | 0.1% | new |
| 23 | GOLDMAN SACHS GROUP INCNEW | 85,180 | $27,062 | 0.0% | 0.1% | new |
| 24 | JMN Financial LLCNEW | 76,748 | $24,383 | 0.0% | 0% | new |
| 25 | BlackRock, Inc. | 69,678 | $22,137 | 0.0% | 0% | -77.0% |
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.