Mereo BioPharma Group plc (MREO) — Institutional Holders, Q2 2026
61 institutional investment managers reported a MREO position on SEC Form 13F-HR for the quarter ended June 30, 2026, with a combined reported value of $18.0M. Every filer is listed below, ranked by position value. Put and call option positions are excluded, and a firm filing several lots or share classes is shown once with its total.
MREO in Q2 2026: what funds did
Funds that filed a 13F for both Q1 2026 and Q2 2026, by what they did with the common stock. Share counts are adjusted for any split between the two quarters; dollar figures are the change in shares at this quarter’s price.
Biggest buyers
- TWO SIGMA INVESTMENTSAdded · +1,131,402 sh+$359.4K
- Ishara InvestmentsNew · +768,750 sh+$244.2K
- JANE STREET GROUPAdded · +634,971 sh+$201.7K
- CITADEL ADVISORSNew · +444,158 sh+$141.1K
- NOMURANew · +104,361 sh+$33.2K
Biggest sellers
- EcoR1 CapitalTrimmed · -12,368,855 sh-$3.9M
- Newtyn ManagementTrimmed · -4,079,056 sh-$1.3M
- MILLENNIUM MANAGEMENTSold out · -3,559,103 sh-$1.1M
- MARSHALL WACE, LLPTrimmed · -507,103 sh-$161.1K
- Knott David M JrSold out · -300,337 sh-$95.4K
MREO 13F holders ranked 1–61 of 61
| # | Institution | Shares | Value | % of portfolio | QoQShares vs Q1 2026 |
|---|---|---|---|---|---|
| 1 | Rubric Capital Management#1 · 15,307,347 sh | 15,307,347 | $4.9M | 0.04% | 0.0% |
| 2 | 683 Capital Management#2 · 11,777,856 sh | 11,777,856 | $3.7M | 0.18% | -1.9% |
| 3 | BANK OF AMERICA#3 · 8,195,281 sh | 8,195,281 | $2.6M | <0.01% | 0.0% |
| 4 | Defilade Capital Management, L.P.#4 · 7,558,756 sh | 7,558,756 | $2.4M | 0.32% | 0.0% |
| 5 | Newtyn Management#5 · 3,000,000 sh | 3,000,000 | $953.1K | 0.12% | -57.6% |
| 6 | Tejara Capital Ltd#6 · 2,037,520 sh | 2,037,520 | $647.3K | 0.27% | 0.0% |
| 7 | UBS Group AG#7 · 1,447,627 sh | 1,447,627 | $460.3K | <0.01% | -2.9% |
| 8 | TWO SIGMA INVESTMENTS#8 · 1,319,241 sh | 1,319,241 | $419.1K | <0.01% | +602.3% |
| 9 | EcoR1 Capital#9 · 1,000,000 sh | 1,000,000 | $317.7K | 0.02% | -92.5% |
| 10 | JANE STREET GROUP#10 · 774,944 sh | 774,944 | $246.2K | 0.00% | +453.6% |
| 11 | Ishara Investments#11 · 768,750 sh | 768,750 | $244.2K | 0.18% | New |
| 12 | Wealthspire Advisors#12 · 765,000 sh | 765,000 | $243.0K | <0.01% | -3.9% |
| 13 | CITADEL ADVISORS#13 · 444,158 sh | 444,158 | $141.1K | 0.00% | New |
| 14 | Rangeley Capital#14 · 329,200 sh | 329,200 | $104.6K | 0.10% | 0.0% |
| 15 | SUSQUEHANNA INTERNATIONAL GROUP, LLP#15 · 213,270 sh | 213,270 | $67.8K | 0.00% | +8.9% |
| 16 | MARSHALL WACE, LLP#16 · 179,884 sh | 179,884 | $57.6K | 0.00% | -73.8% |
| 17 | XTX Topco Ltd#17 · 174,481 sh | 174,481 | $55.4K | <0.01% | +106.6% |
| 18 | GROUP ONE TRADING, L.P.#18 · 167,515 sh | 167,515 | $53.2K | <0.01% | -50.1% |
| 19 | STATE STREET#19 · 134,772 sh | 134,772 | $42.8K | 0.00% | +1.0% |
| 20 | NOMURA#20 · 104,361 sh | 104,361 | $33.2K | 0.00% | New |
| 21 | James J. Burns & Company#21 · 95,400 sh | 95,400 | $30.3K | — | New |
| 22 | Quarry#22 · 93,750 sh | 93,750 | $29.8K | <0.01% | New |
| 23 | GOLDMAN SACHS GROUP#23 · 85,180 sh | 85,180 | $27.1K | 0.00% | New |
| 24 | JMN Financial#24 · 76,748 sh | 76,748 | $24.4K | 0.02% | New |
| 25 | BlackRock#25 · 69,678 sh | 69,678 | $22.1K | 0.00% | -77.0% |
| 26 | JPMORGAN CHASE#26 · 58,531 sh | 58,531 | $19.4K | 0.00% | +167.9% |
| 27 | Virtu Financial#27 · 61,285 sh | 61,285 | $19.0K | <0.01% | +68.1% |
| 28 | RENAISSANCE TECHNOLOGIES#28 · 52,100 sh | 52,100 | $16.6K | 0.00% | +7.6% |
| 29 | Significant Wealth Partners#29 · 32,677 sh | 32,677 | $10.4K | 0.01% | +27.5% |
| 30 | Clear Harbor Asset Management#30 · 32,000 sh | 32,000 | $10.1K | <0.01% | -8.6% |
| 31 | RHUMBLINE ADVISERS#31 · 26,784 sh | 26,784 | $8.5K | 0.00% | +36.8% |
| 32 | Centiva Capital#32 · 25,000 sh | 25,000 | $7.9K | <0.01% | 0.0% |
| 33 | Engineers Gate Manager#33 · 23,953 sh | 23,953 | $7.6K | <0.01% | 0.0% |
| 34 | SIMPLEX TRADING#34 · 18,780 sh | 18,780 | $6.0K | 0.00% | New |
| 35 | Newbridge Financial Services Group#35 · 18,750 sh | 18,750 | $6.0K | — | 0.0% |
| 36 | OneDigital Investment Advisors#36 · 18,300 sh | 18,300 | $5.8K | 0.00% | 0.0% |
| 37 | MORGAN STANLEY#37 · 16,731 sh | 16,731 | $5.3K | 0.00% | +1.9% |
| 38 | IHT Wealth Management#38 · 15,000 sh | 15,000 | $4.8K | <0.01% | 0.0% |
| 39 | TWO SIGMA SECURITIES#39 · 12,900 sh | 12,900 | $4.1K | <0.01% | New |
| 40 | J. Safra Sarasin Holding AG#40 · 12,841 sh | 12,841 | $4.1K | — | New |
| 41 | SG Americas Securities#41 · 12,802 sh | 12,802 | $4.0K | 0.00% | New |
| 42 | MML INVESTORS SERVICES#42 · 12,200 sh | 12,200 | $3.9K | 0.00% | 0.0% |
| 43 | World Investment Advisors#43 · 10,000 sh | 10,000 | $3.3K | <0.01% | 0.0% |
| 44 | Astoria Portfolio Advisors#44 · 10,000 sh | 10,000 | $3.2K | <0.01% | 0.0% |
| 45 | GAMMA Investing#45 · 9,308 sh | 9,308 | $3.0K | — | -51.7% |
| 46 | SRS Capital Advisors#46 · 5,819 sh | 5,819 | $1.8K | 0.00% | +45.5% |
| 47 | Rockefeller Capital Management L.P.#47 · 2,000 sh | 2,000 | $635.00 | 0.00% | 0.0% |
| 48 | OSAIC#48 · 1,500 sh | 1,500 | $479.00 | 0.00% | 0.0% |
| 49 | Allworth Financial#49 · 1,500 sh | 1,500 | $477.00 | 0.00% | 0.0% |
| 50 | Markowski Investments#50 · 1,500 sh | 1,500 | $477.00 | <0.01% | — |
| 51 | New England Capital Financial Advisors#51 · 300 sh | 300 | $96.00 | 0.00% | 0.0% |
| 52 | WELLS FARGO & COMPANY#52 · 231 sh | 231 | $73.00 | 0.00% | +0.4% |
| 53 | SBI Securities , Ltd.#53 · 114 sh | 114 | $36.00 | — | 0.0% |
| 54 | EverSource Wealth Advisors#54 · 100 sh | 100 | $32.00 | 0.00% | +1328.6% |
| 55 | CITIGROUP#55 · 52 sh | 52 | $17.00 | 0.00% | New |
| 56 | US BANCORP \DE\#56 · 13 sh | 13 | $4.00 | 0.00% | 0.0% |
| 57 | BNP PARIBAS FINANCIAL MARKETS#57 · 3 sh | 3 | $1.00 | 0.00% | 0.0% |
| 58 | Axiom Investment Management#58 · 1 sh | 1 | $0.00 | 0.00% | 0.0% |
| 59 | Integrated Wealth Concepts#59 · 1 sh | 1 | $0.00 | 0.00% | New |
| 60 | Caitong International Asset Management , Ltd#60 · 1 sh | 1 | $0.00 | 0.00% | New |
| 61 | SIT INVESTMENT ASSOCIATES#61 · 970 sh | 970 | $0.00 | 0.00% | 0.0% |
Funds that sold out of MREO in Q2 2026 (17)
Held MREO at the end of Q1 2026 and filed a Q2 2026 13F without it. Not in the list above, because they no longer hold it. Largest prior position first.
| Institution | Shares sold | Value in Q1 2026 |
|---|---|---|
| MILLENNIUM MANAGEMENT3,559,103 sh | 3,559,103 | $1.2M |
| Knott David M Jr300,337 sh | 300,337 | $99.1K |
| ACADIAN ASSET MANAGEMENT209,084 sh | 209,084 | $68.0K |
| ADAR1 Capital Management150,000 sh | 150,000 | $49.5K |
| Forefront Analytics127,778 sh | 127,778 | $42.2K |
| Virtus Investment Advisers125,662 sh | 125,662 | $41.5K |
| GEODE CAPITAL MANAGEMENT92,534 sh | 92,534 | $30.5K |
| Caption Management64,064 sh | 64,064 | $21.1K |
| SmartHarvest Portfolios49,512 sh | 49,512 | $16.3K |
| StoneX Group36,873 sh | 36,873 | $12.2K |
| Independent Advisor Alliance35,227 sh | 35,227 | $11.6K |
| Three Magnolias Financial Advisors19,000 sh | 19,000 | $6.3K |
| Baader Bank Aktiengesellschaft12,330 sh | 12,330 | $2.7K |
| BARCLAYS PLC2,496 sh | 2,496 | $824.00 |
| MAI Capital Management309 sh | 309 | $102.00 |
| Sound Income Strategies66 sh | 66 | $22.00 |
| NATIONAL BANK OF CANADA46 sh | 46 | $15.00 |
Source: Form 13F-HR filings on SEC EDGAR, Q2 2026. Values are as reported by each manager at quarter end. “% of portfolio” is the position’s share of the manager’s total reported 13F value for the same quarter. “New” means the manager filed a 13F for Q1 2026 without this position; a dash means no comparison is available. Where a manager’s own filing is internally inconsistent its value is withheld and it is listed last. 13F data shows reported holdings, not recommendations.