Mereo Biopharma Group PL-ADRMREO
13F holders, Q3 2025 (September 30)84holders −2
14new positions
16sold out
3famous investors
$2.05avg. 13F price*
At the end of Q3 2025, 84 institutions reported holding Mereo Biopharma Group PL-ADR (MREO) in their 13F filings, down 2 from Q2 2025. 14 opened new positions and 16 sold out. The largest holders were Janus Henderson Group PLC ($33.6M), Rubric Capital Management LP ($31.5M) and Frazier Life Sciences Management, L.P. ($19.4M). 3 famous investors held it, including Ken Griffin (0.0% of Citadel Advisors's portfolio), Jim Simons / Peter Brown (0.0% of Renaissance Technologies's portfolio) and Israel Englander (0.0% of Millennium Management's portfolio).
- Company
- Mereo Biopharma Group PL-ADR
- CUSIP
- 589492107
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q2 2025 → Q3 2025
| Institutions | Total Value | |
|---|---|---|
| New Positions | 14 | $8.5M |
| Exits | 16 | $20.7M |
All 13F filers, Q2 2025 → Q3 2025: 15,599,509 shares bought and 14,110,058 shares sold, net +1,489,451 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 84 holders
| Janus Henderson Group PLC | 0.02% | Reduce -7.9% | 16,290,130 | $33.6M |
| Rubric Capital Management LP | 0.42% | No change | 15,307,347 | $31.5M |
| Frazier Life Sciences Management, L.P. | 0.58% | No change | 9,440,112 | $19.4M |
| Mangrove Partners Im, LLC | 1.34% | Reduce -9.8% | 7,790,580 | $16.0M |
| Aberdeen Group plc | 0.02% | Add +82.9% | 5,538,699 | $11.4M |
| 683 Capital Management, LLC | 0.96% | Add +12.1% | 4,875,000 | $10.0M |
| Rock Springs Capital Management LP | 0.55% | Add +2.4% | 4,570,649 | $9.4M |
| Clearline Capital LP | 0.68% | Add +6.0% | 3,834,163 | $7.9M |
| Alkeon Capital Management LLC | 0.03% | Reduce -21.3% | 3,698,100 | $7.6M |
| Morgan Stanley | 0.00% | Add +326.1% | 3,346,347 | $6.9M |
| Citadel Advisors | 0.01% | Add +317.0% | 3,171,632 | $6.5M |
| Goldman Sachs Group Inc. | 0.00% | Reduce -23.5% | 2,364,024 | $4.9M |
| Tejara Capital Ltd | 2.15% | Reduce -21.5% | 1,906,844 | $3.9M |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | 0.00% | New | 1,906,775 | $3.9M |
| Schonfeld Strategic Advisors LLC | 0.02% | Add +90.5% | 1,732,724 | $3.6M |
| FMR LLC | 0.00% | Reduce -1.6% | 1,454,900 | $3.0M |
| Blue Owl Capital Holdings LP | 0.81% | New | 1,250,000 | $2.6M |
| Two Sigma Investments, LP | 0.00% | Add +65.1% | 1,088,096 | $2.2M |
| UBS Group AG | 0.00% | Add +159.9% | 970,667 | $2.0M |
| Monaco Asset Management SAM | 0.74% | Add +139.5% | 945,915 | $1.9M |
| Marshall Wace, LLP | 0.00% | No change | 767,744 | $1.6M |
| Renaissance Technologies | 0.00% | Reduce -60.1% | 590,871 | $1.2M |
| Logos Global Management LP | 0.10% | New | 500,000 | $1.0M |
| Susquehanna International Group, LLP | 0.00% | Add +36.5% | 493,378 | $1.0M |
| Artia Global Partners LP | 0.17% | No change | 475,361 | $979K |
| Jane Street Group, LLC | 0.00% | Add +82.8% | 452,362 | $932K |
| BlackRock, Inc. | 0.00% | Reduce -2.5% | 444,004 | $915K |
| Bank of America Corp. | 0.00% | Reduce -0.0% | 438,622 | $904K |
| Millennium Management | 0.00% | Reduce -43.3% | 337,503 | $695K |
| Knott David M Jr | 0.26% | Reduce -6.0% | 300,337 | $619K |
| Soleus Capital Management, L.P. | 0.03% | Reduce -50.0% | 299,711 | $617K |
| Hudson Bay Capital Management LP | 0.00% | Reduce -41.1% | 265,000 | $546K |
| Knoll Capital Management, LLC | 0.29% | No change | 260,470 | $537K |
| Acadian Asset Management LLC | 0.00% | New | 256,378 | $522K |
| Two Sigma Advisers, LP | 0.00% | Add +67.5% | 242,200 | $499K |
| Simplex Trading, LLC | 0.01% | Reduce -2.4% | 196,269 | $404K |
| XTX Topco Ltd | 0.02% | Add +175.5% | 191,037 | $394K |
| Caption Management, LLC | 0.02% | Reduce -3.9% | 189,914 | $391K |
| Group One Trading LLC | 0.01% | Reduce -2.1% | 136,588 | $281K |
| State Street Corp. | 0.00% | Add +195.3% | 132,701 | $273K |
| Cantor Fitzgerald, L. P. | 0.00% | Reduce -67.9% | 110,000 | $227K |
| Nomura Holdings Inc. | 0.00% | Reduce -17.0% | 103,800 | $214K |
| Geode Capital Management, LLC | 0.00% | No change | 92,534 | $191K |
| Atle Fund Management AB | 0.62% | No change | 764,901 | $167K |
| Clear Harbor Asset Management, LLC | 0.01% | Add +83.3% | 77,000 | $159K |
| Gsa Capital Partners LLP | 0.01% | New | 58,145 | $120K |
| Aquatic Capital Management LLC | 0.00% | Add +99.5% | 53,712 | $111K |
| Significant Wealth Partners LLC | 0.05% | Add +114.8% | 47,814 | $98K |
| Virtus Investment Advisers, LLC | 0.02% | Add +21.0% | 40,930 | $84K |
| Avanza Fonder AB | 0.00% | No change | 38,235 | $79K |
| Three Magnolias Financial Advisors, LLC | 0.05% | No change | 37,000 | $76K |
| HRT Financial LP | 0.00% | New | 34,852 | $71K |
| Forefront Analytics, LLC | 0.07% | Add +73.4% | 33,180 | $68K |
| Forefront Wealth Partners, LLC | 0.02% | New | 33,180 | $68K |
| Squarepoint Ops LLC | 0.00% | Add +45.4% | 30,055 | $62K |
| Centiva Capital, LP | 0.00% | No change | 25,000 | $52K |
| Federation des caisses Desjardins du Quebec | 0.00% | New | 21,271 | $44K |
| Ascentis Independent Advisors | 0.01% | No change | 19,900 | $41K |
| OneDigital Investment Advisors LLC | 0.00% | No change | 18,300 | $38K |
| PFG Investments, LLC | 0.00% | Reduce -54.2% | 17,150 | $35K |
| Sheets Smith Investment Management | 0.02% | No change | 16,890 | $35K |
| Virtu Financial LLC | 0.00% | New | 15,970 | $33K |
| State of New Jersey Common Pension Fund D | 0.00% | New | 15,644 | $32K |
| NFSG Corp | 0.00% | No change | 13,000 | $27K |
| Scientech Research LLC | 0.01% | New | 10,124 | $21K |
| Level Four Advisory Services, LLC | 0.00% | No change | 10,000 | $21K |
| GAMMA Investing LLC | 0.00% | Reduce -0.8% | 9,181 | $19K |
| Rhumbline Advisers | 0.00% | Reduce -7.7% | 9,122 | $19K |
| Caitong International Asset Management Co., Ltd | 0.01% | Add +86.5% | 8,476 | $17K |
| Osaic Holdings, Inc. | 0.00% | Add +5.6% | 5,677 | $10K |
| Arax Advisory Partners | 0.00% | No change | 4,000 | $8K |
| Rockefeller Capital Management L.P. | 0.00% | New | 2,000 | $4K |
| Allworth Financial LP | 0.00% | Reduce -3.9% | 1,573 | $3K |
| GPS Wealth Strategies Group, LLC | 0.00% | No change | 1,500 | $3K |
| Wealthspire Advisors, LLC | 0.00% | New | 1,026 | $2K |
| Sit Investment Associates Inc. | 0.00% | No change | 970 | $2K |
| EverSource Wealth Advisors, LLC | 0.00% | Reduce -11.3% | 417 | $859 |
| MAI Capital Management | 0.00% | No change | 309 | $637 |
| New England Capital Financial Advisors LLC | 0.00% | No change | 300 | $618 |
| Wells Fargo & Company | 0.00% | No change | 230 | $473 |
| Principal Securities, Inc. | 0.00% | No change | 75 | $155 |
| US Bancorp \de | 0.00% | No change | 13 | $27 |
| BNP Paribas Financial Markets | 0.00% | No change | 3 | $6 |
| Royal Bank of Canada | 0.00% | New | 5 | $0 |
"% of holder's portfolio" is MREO's weight in each manager's 13F, not the share of Mereo Biopharma Group PL-ADR the manager owns.