Marshall Wace’s Seres Therapeutics MCRB Stock Holding History

Marshall Wace’s Portfolio MCRB Stock Details MCRB Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$1.24M	Buy	139,539 +19,362	+16%	+$227K	﹤0.01%	2032
2025 Q4	$1.79M	Sell	120,177 -5,423	-4%	-$94.6K	﹤0.01%	1630
2025 Q3	$2.42M	Buy	125,600 +34,195	+37%	+$546K	﹤0.01%	1523
2025 Q2	$1.02M	Buy	+91,405	New	+$804K	﹤0.01%	1844
2022 Q3	–	Sell	-17,045	Closed	-$1.17M	–	3613
2022 Q2	$1.17M	Buy	+17,045	New	+$1.47M	﹤0.01%	2351
2022 Q1	–	Sell	-6,150	Closed	-$1.02M	–	3735
2021 Q4	$1.02M	Sell	6,150 -5,448	-47%	-$866K	﹤0.01%	2461
2021 Q3	$1.61M	Buy	+11,598	New	+$2.27M	0.01%	1699
2019 Q4	–	Sell	-3,242	Closed	-$260K	–	1923
2019 Q3	$260K	Sell	3,242 -19,093	-85%	-$1.26M	﹤0.01%	1237
2019 Q2	$1.44M	Buy	22,335 +16,205	+264%	+$1.54M	0.01%	854
2019 Q1	$842K	Buy	+6,130	New	+$747K	0.01%	991

Other funds holding MCRB

Flagship Pioneering Cambridge, Massachusetts $1.16B AUM 67.93% 1-Year Est. Return

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

Vontobel Holding Zurich, Switzerland $31.4B AUM 31.97% 1-Year Est. Return

Susquehanna International Group Bala Cynwyd, Pennsylvania $893B AUM 36.07% 1-Year Est. Return

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return

American Century Companies Kansas City, Missouri $194B AUM 35% 1-Year Est. Return

VFT

Vanguard Fiduciary Trust Malvern, Pennsylvania $396B AUM

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

Charles Schwab San Francisco, California $654B AUM 26.35% 1-Year Est. Return

Marshall Wace's MCRB Position: Q1 2026 in Review

Marshall Wace increased its Seres Therapeutics (MCRB) stake by 16% in Q1 2026, buying an estimated $227K and bringing the position to 139,539 shares worth $1.24M. The position accounts for ﹤0.01% of the portfolio, ranked #2032.

Marshall Wace first reported a position in MCRB in Q1 2019 and has held it in 10 quarters since. The position peaked at $2.42M in Q3 2025. 33 funds tracked by Wall St. Rank hold MCRB as of Q1 2026.

Marshall Wace held 139,539 shares of Seres Therapeutics worth $1.24M as of Q1 2026.
Marshall Wace bought 19,362 Seres Therapeutics shares in Q1 2026, an estimated $227K.
Seres Therapeutics made up ﹤0.01% of Marshall Wace's portfolio in Q1 2026, its #2032 holding.
Marshall Wace first reported a position in Seres Therapeutics in Q1 2019 and has held it in 10 quarters since.
Marshall Wace's Seres Therapeutics position peaked at $2.42M in Q3 2025.
33 funds tracked by Wall St. Rank held Seres Therapeutics as of Q1 2026.

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