Marshall Wace’s Mereo BioPharma MREO Stock Holding History

Marshall Wace’s Portfolio MREO Stock Details MREO Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$227K	Buy	+686,987	New	+$295K	﹤0.01%	2736
2025 Q4	–	Sell	-767,744	Closed	-$1.58M	–	3275
2025 Q3	$1.58M	Hold	767,744	–	–	﹤0.01%	1724
2025 Q2	$2.08M	Hold	767,744	–	–	﹤0.01%	1545
2025 Q1	$1.73M	Sell	767,744 -98,573	-11%	-$279K	﹤0.01%	1532
2024 Q4	$3.03M	Sell	866,317 -162,195	-16%	-$637K	﹤0.01%	1282
2024 Q3	$4.23M	Sell	1,028,512 -115,539	-10%	-$478K	0.01%	1061
2024 Q2	$4.12M	Buy	+1,144,051	New	+$3.71M	0.01%	1085
2024 Q1	–	Sell	-14,883	Closed	-$34.4K	–	2679
2023 Q4	$34.4K	Buy	+14,883	New	+$28.5K	﹤0.01%	2090
2022 Q1	–	Sell	-98,288	Closed	-$157K	–	3760
2021 Q4	$157K	Buy	+98,288	New	+$197K	﹤0.01%	3245
2021 Q3	–	Sell	-44,682	Closed	-$142K	–	3273
2021 Q2	$142K	Sell	44,682 -28,876	-39%	-$96.9K	﹤0.01%	2501
2021 Q1	$248K	Buy	+73,558	New	+$260K	﹤0.01%	2191

Other funds holding MREO

RCMNY

Rubric Capital Management (New York) New York $9.44B AUM 68.42% 1-Year Est. Return

EcoR1 Capital San Francisco, California $2.36B AUM 204.53% 1-Year Est. Return

6CM

683 Capital Management New York $1.92B AUM 85.52% 1-Year Est. Return

Bank of America Charlotte, North Carolina $1.37T AUM 24.88% 1-Year Est. Return

DCM

Defilade Capital Management Emeryville, California $712M AUM

Newtyn Management New York $936M AUM 27.23% 1-Year Est. Return

Millennium Management New York $240B AUM 35.51% 1-Year Est. Return

Tejara Capital London, United Kingdom $303M AUM 5.43% 1-Year Est. Return

UBS Group Zurich, Switzerland $666B AUM 30.12% 1-Year Est. Return

WANY

Wealthspire Advisors (New York) New York $12.7B AUM 17.31% 1-Year Est. Return

Marshall Wace's MREO Position: Q1 2026 in Review

Marshall Wace opened a new position in Mereo BioPharma (MREO) in Q1 2026: 686,987 shares worth $227K. The stake represents ﹤0.01% of the portfolio and ranks #2736 among its holdings. This is a return to the name: Marshall Wace previously reported a position in MREO as recently as Q3 2025.

Marshall Wace first reported a position in MREO in Q1 2021 and has held it in 11 quarters since. The position peaked at $4.23M in Q3 2024. 63 funds tracked by Wall St. Rank hold MREO as of Q1 2026.

Marshall Wace held 686,987 shares of Mereo BioPharma worth $227K as of Q1 2026.
Mereo BioPharma was a new Marshall Wace position in Q1 2026.
Mereo BioPharma made up ﹤0.01% of Marshall Wace's portfolio in Q1 2026, its #2736 holding.
Marshall Wace first reported a position in Mereo BioPharma in Q1 2021 and has held it in 11 quarters since.
Marshall Wace's Mereo BioPharma position peaked at $4.23M in Q3 2024.
63 funds tracked by Wall St. Rank held Mereo BioPharma as of Q1 2026.

Based on Marshall Wace's 13F filing for Q1 2026, filed 15 May 2026.