Jane Street’s Mayville Engineering Co MEC Stock Holding History

Jane Street’s Portfolio MEC Stock Details MEC Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	–	Sell	-53,074	Closed	-$994K	–	12425
2025 Q4	$994K	Buy	53,074 +34,344	+183%	+$560K	﹤0.01%	6134
2025 Q3	$258K	Buy	+18,730	New	+$282K	﹤0.01%	9210
2025 Q2	–	Sell	-47,194	Closed	-$634K	–	10391
2025 Q1	$634K	Buy	47,194 +28,946	+159%	+$435K	﹤0.01%	6427
2024 Q4	$287K	Buy	18,248 +4,013	+28%	+$73.4K	﹤0.01%	7806
2024 Q3	$300K	Buy	14,235 +2,909	+26%	+$54.4K	﹤0.01%	8036
2024 Q2	$189K	Buy	+11,326	New	+$171K	﹤0.01%	8436
2023 Q3	–	Sell	-25,580	Closed	-$319K	–	9084
2023 Q2	$319K	Sell	25,580 -27,492	-52%	-$347K	﹤0.01%	7024
2023 Q1	$792K	Buy	+53,072	New	+$773K	﹤0.01%	5459
2021 Q1	–	Sell	-10,074	Closed	-$135K	–	9400
2020 Q4	$135K	Buy	+10,074	New	+$111K	﹤0.01%	7113

Other funds holding MEC

Allspring Global Investments Charlotte, North Carolina $59.7B AUM 29.08% 1-Year Est. Return

Dimensional Fund Advisors Austin, Texas $481B AUM 30.42% 1-Year Est. Return

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

PCM

Portolan Capital Management Boston, Massachusetts $1.88B AUM 115.74% 1-Year Est. Return

Royce & Associates New York $10.1B AUM 42.88% 1-Year Est. Return

EVR Research Richmond, Virginia $250M AUM 41.5% 1-Year Est. Return

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

William Blair & Company Chicago, Illinois $34.9B AUM 18.88% 1-Year Est. Return

First Eagle Investment Management New York $59B AUM 32.99% 1-Year Est. Return

GIM

Granahan Investment Management Waltham, Massachusetts $2.07B AUM 56.45% 1-Year Est. Return

Jane Street's MEC Position: Q1 2026 in Review

Jane Street sold out of Mayville Engineering Co (MEC) in Q1 2026, closing a stake of 53,074 shares — an estimated $994K sold.

Jane Street first reported a position in MEC in Q4 2020 and held it in 9 quarters. The position peaked at $994K in Q4 2025. 124 funds tracked by Wall St. Rank hold MEC as of Q1 2026.

Jane Street reported no remaining Mayville Engineering Co position as of Q1 2026 after selling out during the quarter.
Jane Street sold 53,074 Mayville Engineering Co shares in Q1 2026, an estimated $994K.
Jane Street first reported a position in Mayville Engineering Co in Q4 2020 and held it in 9 quarters.
Jane Street's Mayville Engineering Co position peaked at $994K in Q4 2025.
124 funds tracked by Wall St. Rank held Mayville Engineering Co as of Q1 2026.

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