Jane Street’s MFS Active Mid Cap ETF MMID Stock Holding History

Jane Street’s Portfolio MMID Stock Details MMID Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	–	Sell	-8,399	Closed	-$211K	–	13592
2025 Q4	$211K	Sell	8,399 -13,266	-61%	-$331K	﹤0.01%	9613
2025 Q3	$544K	Buy	+21,665	New	+$539K	﹤0.01%	7668

Other funds holding MMID

Commonwealth Equity Services Waltham, Massachusetts $79.5B AUM 27.1% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

Jane Street's MMID Position: Q1 2026 in Review

Jane Street sold out of MFS Active Mid Cap ETF (MMID) in Q1 2026, closing a stake of 8,399 shares — an estimated $211K sold.

Jane Street first reported a position in MMID in Q3 2025 and held it in 2 quarters. The position peaked at $544K in Q3 2025. 2 funds tracked by Wall St. Rank hold MMID as of Q1 2026.

Jane Street reported no remaining MFS Active Mid Cap ETF position as of Q1 2026 after selling out during the quarter.
Jane Street sold 8,399 MFS Active Mid Cap ETF shares in Q1 2026, an estimated $211K.
Jane Street first reported a position in MFS Active Mid Cap ETF in Q3 2025 and held it in 2 quarters.
Jane Street's MFS Active Mid Cap ETF position peaked at $544K in Q3 2025.
2 funds tracked by Wall St. Rank held MFS Active Mid Cap ETF as of Q1 2026.

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