Marshall Wace’s Spero Therapeutics SPRO Stock Holding History

Marshall Wace’s Portfolio SPRO Stock Details SPRO Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$368K	Buy	+157,072	New	+$373K	﹤0.01%	2587
2023 Q2	–	Sell	-64,388	Closed	-$93.4K	–	2940
2023 Q1	$93.4K	Buy	64,388 +13,471	+26%	+$22.6K	﹤0.01%	2505
2022 Q4	$88.1K	Sell	50,917 -135,653	-73%	-$253K	﹤0.01%	2803
2022 Q3	$374K	Buy	186,570 +150,201	+413%	+$149K	﹤0.01%	2857
2022 Q2	$27K	Buy	36,369 +10,342	+40%	+$30.1K	﹤0.01%	3352
2022 Q1	$227K	Buy	+26,027	New	+$267K	﹤0.01%	3059
2019 Q3	–	Sell	-17,699	Closed	-$204K	–	1913
2019 Q2	$204K	Buy	17,699 +14,625	+476%	+$176K	﹤0.01%	1245
2019 Q1	$39K	Buy	+3,074	New	+$32.6K	﹤0.01%	1563

Other funds holding SPRO

GSK plc London $599M AUM

Pfizer New York $239M AUM 232.47% 1-Year Est. Return

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

Renaissance Technologies New York $63.9B AUM 45.56% 1-Year Est. Return

Alphabet Inc Mountain View, California $4.02B AUM 215.74% 1-Year Est. Return

Two Sigma Investments New York $124B AUM 33.93% 1-Year Est. Return

AFM

Anson Funds Management Dallas, Texas $2.29B AUM 370.24% 1-Year Est. Return

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

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

Citadel Advisors Miami, Florida $618B AUM 30.34% 1-Year Est. Return

Marshall Wace's SPRO Position: Q1 2026 in Review

Marshall Wace opened a new position in Spero Therapeutics (SPRO) in Q1 2026: 157,072 shares worth $368K. The stake represents ﹤0.01% of the portfolio and ranks #2587 among its holdings. This is a return to the name: Marshall Wace previously reported a position in SPRO as recently as Q1 2023.

Marshall Wace first reported a position in SPRO in Q1 2019 and has held it in 8 quarters since. The position peaked at $374K in Q3 2022. 50 funds tracked by Wall St. Rank hold SPRO as of Q1 2026.

Marshall Wace held 157,072 shares of Spero Therapeutics worth $368K as of Q1 2026.
Spero Therapeutics was a new Marshall Wace position in Q1 2026.
Spero Therapeutics made up ﹤0.01% of Marshall Wace's portfolio in Q1 2026, its #2587 holding.
Marshall Wace first reported a position in Spero Therapeutics in Q1 2019 and has held it in 8 quarters since.
Marshall Wace's Spero Therapeutics position peaked at $374K in Q3 2022.
50 funds tracked by Wall St. Rank held Spero Therapeutics as of Q1 2026.

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