Mereo BioPharma Group plc (MREO) Ownership
MREO ownership summary
as of October 17, 2026- Institutions
- 35.5% of shares outstanding
- Insiders
- 0.75% of shares outstanding
- Shares outstanding
- 159.7M
- Float
- 125.0M shares available to trade
- Short interest
- 2.06% 2.7M shares short
- Days to cover
- 1.42 short interest down 12.9% vs prior month
- Institutions 35.47%
- Insiders 0.75%
- Other investors 63.79%
MREO top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Rubric Capital Management LP | 9.59% | 15.3M | $4.6M | — | June 30, 2026 |
| 2 | 683 Capital Management LLC | 7.51% | 12.0M | $3.6M | −3.0M (−20.1%) | March 31, 2026 |
| 3 | Bank of America Corp | 5.13% | 8.2M | $2.5M | −6 (−0.0%) | June 30, 2026 |
| 4 | Defilade Capital Management, L.P. | 4.73% | 7.6M | $2.3M | — | June 30, 2026 |
| 5 | Newtyn Management LLC | 1.88% | 3.0M | $909,000 | −4.1M (−57.6%) | June 30, 2026 |
| 6 | Tejara Capital Ltd | 1.28% | 2.0M | $617,369 | — | June 30, 2026 |
| 7 | UBS Group AG | 0.91% | 1.4M | $438,631 | −42,501 (−2.9%) | June 30, 2026 |
| 8 | Two Sigma Investments LLC | 0.83% | 1.3M | $399,730 | +1.1M (+602.3%) | June 30, 2026 |
| 9 | EcoR1 Capital, LLC | 0.63% | 1.0M | $303,000 | −12.4M (−92.5%) | June 30, 2026 |
| 10 | Jane Street Group LLC | 0.49% | 775K | $234,808 | +634,971 (+453.6%) | June 30, 2026 |
| 11 | Ishara Investments LP | 0.48% | 769K | $232,931 | +768,750 (0.0%) | June 30, 2026 |
| 12 | Sontag Advisory LLC | 0.48% | 765K | $231,795 | −31,036 (−3.9%) | June 30, 2026 |
| 13 | Citadel Advisors Llc | 0.28% | 444K | $134,580 | +444,158 (0.0%) | June 30, 2026 |
| 14 | Susquehanna International Group, LLP | 0.13% | 213K | $64,621 | +17,350 (+8.9%) | June 30, 2026 |
| 15 | Marshall Wace Asset Management Ltd | 0.11% | 180K | $54,505 | −507,103 (−73.8%) | June 30, 2026 |
| 16 | XTX Topco Ltd | 0.11% | 174K | $52,868 | +90,012 (+106.6%) | June 30, 2026 |
| 17 | Group One Trading, LLC | 0.10% | 168K | $50,757 | −168,312 (−50.1%) | June 30, 2026 |
| 18 | State Street Corp | 0.08% | 135K | $40,836 | +1,393 (+1.0%) | June 30, 2026 |
| 19 | Nomura Holdings Inc | 0.07% | 104K | $31,621 | +104,361 (0.0%) | June 30, 2026 |
| 20 | James J. Burns & Company, LLC | 0.06% | 95K | $28,906 | +95,400 (0.0%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 9 holders added 3.3M shares and 8 cut 20.2M.
MREO top mutual fund and ETF holders
1 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | International Biotechnology Ord | 0.67% | 1.1M | $323,808 | — | June 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
MREO insider transactions
latest 10| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2024-09-12 | Charles Sermon | Sell | $4.47 | 9,980 | $44,611 |
| 2024-09-12 | Christine Ann Fox | Sell | $4.47 | 9,128 | $40,802 |
| 2024-09-12 | Denise Scots-Knight | Sell | $4.47 | 28,611 | $127,891 |
| 2024-09-12 | John A Lewicki | Sell | $4.47 | 5,212 | $23,298 |
| 2024-08-22 | Deepika Pakianathan | Sell | $4.43 | 105,244 | $466,231 |
| 2024-06-25 | Charles Sermon | Sell | $3.69 | 14,202 | $52,405 |
| 2024-06-25 | Christine Ann Fox | Sell | $3.69 | 12,990 | $47,933 |
| 2024-06-25 | Denise Scots-Knight | Sell | $3.69 | 40,712 | $150,227 |
| 2024-06-25 | John A Lewicki | Sell | $3.69 | 7,416 | $27,365 |
| 2024-05-22 | Alexandra Hughes-Wilson | Sell | $2.97 | 100,432 | $298,283 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
MREO shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns MREO
Institutional investors own 35.5% of Mereo BioPharma's shares and insiders 0.75%. The largest holder is Rubric Capital Management LP with 9.59% of the shares (15.3M), as of June 30, 2026. Among the top 20 institutions, 9 added shares and 8 reduced their stake in the latest filings. Short interest is 2.06% of the float, or 1.42 days of average trading volume. The share count rose 146.1% since 2016.
Related: MREO analyst forecast, MREO key metrics. See the MREO stock overview for the latest quote and news.
MREO ownership FAQ
Who owns the most Mereo BioPharma stock?
The largest shareholders of Mereo BioPharma are Rubric Capital Management LP (9.59%), 683 Capital Management LLC (7.51%), Bank of America Corp (5.13%), Defilade Capital Management, L.P. (4.73%), Newtyn Management LLC (1.88%).
What percentage of Mereo BioPharma is owned by institutions?
Institutions hold 35.5% of Mereo BioPharma's shares outstanding; insiders hold 0.75%.
Which funds own Mereo BioPharma?
The largest fund holders of Mereo BioPharma are International Biotechnology Ord (0.67%).
What is Mereo BioPharma's short interest?
2.7M shares of Mereo BioPharma were sold short, 2.06% of the float; at the average daily volume it would take 1.42 days to cover.
Are insiders buying or selling Mereo BioPharma?
Of the latest 10 reported insider transactions in Mereo BioPharma (since May 22, 2024), 0 were purchases and 10 were sales.
How many shares of Mereo BioPharma are outstanding?
Mereo BioPharma has 159.7M shares outstanding, of which 125.0M are in the public float.