Latest Period
Q1 2026
Security Snapshot
Mereo BioPharma Group plc - Ordinary Shares (MREO) Institutional Ownership
CUSIP: 589492107
13F Institutional Holders and Ownership History from Q2 2019 to Q2 2026
Institutions Reporting
61
Shares (Excl. Options)
75,379,566
Price
$0.33
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- Security type / class
- Equity / Ordinary Shares
- Symbol
- MREO on Nasdaq
- All holders as of 31 Mar 2026
- Q1 2026
- Total 13F shares
- 75,379,566
- Total 13F value
- $24,872,020
- Portfolio coverage rank
- 0%
- Share change
- +13,349,869
- Value change
- +$3,119,018
- Number of holders
- 61
- Shares outstanding
- 795,765,179
- SEC-reported price per share
- $0.32
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
2 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- MREO - Mereo BioPharma Group plc - Ordinary Shares is tracked under CUSIP 589492107.
- 61 institutions reported positions in Q1 2026.
- 7 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 61 to 7 between Q1 2026 and Q2 2026.
- SEC-reported value moved from $24,872,020 to $20,761.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 61 institutions filings for Q1 2026.
Security key
589492107
Latest holder period
Q1 2026
13F holders
61
13D/G owners
7
CIK / CUSIP context first
Open Q1 2026 holders
MREO full holder history
Mereo BioPharma Group plc SEC filings
Mereo BioPharma Group plc company facts
Mereo BioPharma Group plc insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 589492107:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
7
Security
MREO
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| EcoR1 Capital, LLC | 8.4% | -11% | $22,058,611 | -$2,526,389 | 66,844,275 | -10% | EcoR1 Capital, LLC | 31 Mar 2026 |
| 683 Capital Management, LLC | 8.2% | $27,120,426 | 65,083,815 | 683 Capital Management, LLC | 29 Dec 2025 | |||
| ADAGE CAPITAL PARTNERS GP, L.L.C. | 5.6% | $113,730,920 | 43,575,065 | Adage Capital Management, L.P. | 31 Dec 2024 | |||
| BANK OF AMERICA CORP /DE/ | 5.1% | $13,522,232 | 40,976,460 | BANK OF AMERICA CORP /DE/ | 31 Mar 2026 | |||
| MANGROVE PARTNERS IM, LLC | 4.9% | $80,242,974 | 38,952,900 | Mangrove Partners IM, LLC | 30 Sep 2025 | |||
| Rock Springs Capital Management LP | 4.2% | $87,229,423 | 33,421,235 | Rock Springs Capital Management LP | 31 Mar 2025 | |||
| Adage Capital Management, L.P. | 1.1% | $22,194,866 | 8,503,780 | Adage Capital Management, L.P. | 31 Mar 2025 |
As of 31 Mar 2026, 61 institutional investors reported holding 75,379,566 shares of Mereo BioPharma Group plc - Ordinary Shares (MREO). This represents 9.5% of the company’s total 795,765,179 outstanding shares.
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
29
Latest
Q1 2026
Rows shown
1-25 of 29
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q2 | 65,340 | $20,761 | -$5,811 | $0.32 | 7 |
| 2026 Q1 | 75,379,566 | $24,872,020 | +$3,119,018 | $0.33 | 61 |
| 2025 Q4 | 62,032,089 | $25,827,571 | -$114,787,202 | $0.42 | 70 |
| 2025 Q3 | 99,471,712 | $204,984,259 | -$1,910,639 | $2.06 | 82 |
| 2025 Q2 | 98,647,167 | $267,511,231 | -$28,666,960 | $2.71 | 85 |
| 2025 Q1 | 110,598,225 | $250,098,919 | -$12,622,883 | $2.25 | 87 |
| 2024 Q4 | 115,193,969 | $403,099,510 | +$29,662,675 | $3.50 | 90 |
| 2024 Q3 | 105,735,860 | $434,698,726 | +$21,814,008 | $4.11 | 76 |
| 2024 Q2 | 100,520,356 | $361,910,507 | +$59,834,784 | $3.60 | 76 |
| 2024 Q1 | 84,006,001 | $277,272,467 | +$19,427,852 | $3.30 | 77 |
| 2023 Q4 | 78,538,884 | $181,392,642 | +$20,402,688 | $2.31 | 60 |
| 2023 Q3 | 69,934,611 | $90,216,596 | +$9,888,781 | $1.29 | 52 |
| 2023 Q2 | 63,630,062 | $83,982,713 | +$9,810,717 | $1.32 | 48 |
| 2023 Q1 | 60,813,068 | $42,992,107 | -$604,492 | $0.71 | 56 |
| 2022 Q4 | 61,433,344 | $46,074,279 | -$7,738,535 | $0.75 | 57 |
| 2022 Q3 | 67,994,550 | $58,546,462 | -$7,128,601 | $0.86 | 56 |
| 2022 Q2 | 73,625,094 | $82,466,840 | -$16,891,885 | $1.12 | 58 |
| 2022 Q1 | 88,907,613 | $99,569,590 | -$3,071,799 | $1.12 | 54 |
| 2021 Q4 | 90,856,815 | $145,372,152 | -$12,163,504 | $1.60 | 67 |
| 2021 Q3 | 87,544,301 | $211,861,957 | -$26,671,615 | $2.42 | 58 |
| 2021 Q2 | 89,643,356 | $284,079,000 | -$2,186,471 | $3.17 | 68 |
| 2021 Q1 | 90,226,943 | $304,106,740 | +$110,829,354 | $3.37 | 64 |
| 2020 Q4 | 57,138,262 | $204,527,659 | +$139,354,322 | $3.58 | 44 |
| 2020 Q3 | 14,275,529 | $38,070,000 | +$18,635,267 | $2.62 | 22 |
| 2020 Q2 | 7,275,071 | $22,263,000 | +$12,610,604 | $3.06 | 20 |