Jane Street’s Spero Therapeutics SPRO Stock Holding History

Jane Street’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	$88.5K	Buy	+37,800	New	+$89.7K	﹤0.01%	10707

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

Jane Street's SPRO Position: Q1 2026 in Review

Jane Street reduced its Spero Therapeutics (SPRO) stake by 33% in Q1 2026, selling an estimated $123K and leaving 106,345 shares worth $249K. The position accounts for ﹤0.01% of the portfolio, ranked #9639.

Jane Street first reported a position in SPRO in Q1 2021 and has held it in 7 quarters since. The position peaked at $369K in Q4 2025. 50 funds tracked by Wall St. Rank hold SPRO as of Q1 2026.

Jane Street held 106,345 shares of Spero Therapeutics worth $249K as of Q1 2026.
Jane Street sold 51,999 Spero Therapeutics shares in Q1 2026, an estimated $123K.
Spero Therapeutics made up ﹤0.01% of Jane Street's portfolio in Q1 2026, its #9639 holding.
Jane Street first reported a position in Spero Therapeutics in Q1 2021 and has held it in 7 quarters since.
Jane Street's Spero Therapeutics position peaked at $369K in Q4 2025.
50 funds tracked by Wall St. Rank held Spero Therapeutics as of Q1 2026.

Based on Jane Street's 13F filing for Q1 2026, filed 12 May 2026.