Mereo BioPharma Group plc (MREO)
Nasdaq: MREO · Pharmaceutical Preparations · London · filing with the SEC since 2017
Who owns Mereo BioPharma Group plc
As filed with the SECHolders of 5% or more
2
683 Capital Management, LLC holds 8.18% of American Depositary Shares, each representing five ordinary shares, nominal value of 0.003 GBP per share, as its SCHEDULE 13G filed Jan 6, 2026 says.
Directors and officers
13
report now, of 14 people on the record since 2024. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 2 named at left.
Holders of 5% or moreshare of the class, as filed
683 Capital Management, LLC
SCHEDULE 13G · filed Jan 6, 2026 · American Depositary Shares, each representing five ordinary shares, nominal value of 0.003 GBP per share
Adage Capital Management, L.P.
SCHEDULE 13G/A · filed Feb 12, 2025 · Ordinary Shares, nominal value 0.003 GBP per share
Mangrove Partners IM, LLC
SCHEDULE 13G/A · filed Nov 14, 2025 · American Depositary Shares, each representing five ordinary shares, nominal value of (pound)0.003 per share · reported falling below 5%
Rock Springs Capital Management LP
SCHEDULE 13G/A · filed May 15, 2025 · Ordinary Shares, nominal value 0.003, per ordinary share · reported falling below 5%
Bank of America Corporation
SCHEDULE 13G/A · filed Oct 28, 2026 · Ordinary Shares · reported falling below 5%, from 5.1% in May 14, 2026
Adage Capital Management, L.P.
SCHEDULE 13G/A · filed May 12, 2025 · Ordinary Shares, nominal value 0.003 GBP per share · reported falling below 5%
EcoR1 Capital, LLC
SCHEDULE 13G/A · filed Aug 14, 2026 · Ordinary Shares · reported falling below 5%, from 8.4% in May 15, 2026
Northpond Ventures, LP
SCHEDULE 13G/A · filed Feb 17, 2026 · Ordinary Shares, par value GBP 0.003 per share · reported falling below 5%, from 6.9% in Jun 11, 2025
Janus Henderson Group PLC
SCHEDULE 13G/A · filed Feb 17, 2026 · Ordinary Shares · reported falling below 5%, from 10.2% in Nov 14, 2025
Frazier Life Sciences Public Fund, L.P.
SCHEDULE 13G/A · filed Feb 13, 2026 · Ordinary Shares, nominal value EURO0.003 per share, represented by American Depository Shares · reported falling below 5%, from 4.1% in Aug 14, 2025
What MREO reports owning in othersstakes of 5% or more, and other ties
Other ties the annual report names
Astrazeneca
An entity · legal entity · owns, named in the 10-K filed Mar 19, 2026
Insider tradesForm 4
0sales
0purchases
0sales on a scheduled plan
0people selling
$0sold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Sep 30, 2025 to Sep 30, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
2024 runs to Sep 30, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window
No one on the roster filed an open-market trade in the window.