BLAIR WILLIAM & CO/IL

Position in MEC — Mayville Engineering Company, Inc.

CIK 902367 CHICAGO, IL

Position in MEC

as of Jun 30, 2026 · filed Aug 11, 2026 Compact

Position Value

$20,479,906

+$10,332,771 QoQ

Shares Held

546,714

-3.3% QoQ

Ownership

2.14%

of shares outstanding

% of Portfolio

0.06%

of 13F equity value

Holder Rank

#12

of 153 holders

Holding Since

Mar 2023

14 quarters on record

Voting authority Sole 89% Shared 0% None 11%

Industrials · as of Jun 30, 2026

BLAIR WILLIAM & CO/IL holds $71,561,524 across 4 Metal Fabrication names. MEC ranks #2 (28.6% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	ATI	Ati Inc	231,946	$45,716,556
2	MEC	Mayville Engineering Company, Inc. This page	546,714	$20,479,906
3	CRS	Carpenter Technology Corp	4,841	$2,986,122
4	MLI	Mueller Industries Inc	38,704	$2,378,940

14 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-06-30	$20,479,906	546,714	-3.3%	Shares	Sole	2026-08-11
2026-03-31	$10,147,135	565,300	-3.2%	Shares	Sole	2026-05-08
2025-12-31	$10,927,968	583,759	+54.8%	Shares	Sole	2026-02-17
2025-09-30	$5,190,409	377,210	+1.0%	Shares	Sole	2025-11-12
2025-06-30	$5,960,230	373,448	+304.8%	Shares	Sole	2025-07-24
2025-03-31	$1,238,917	92,250	-53.3%	Shares	Sole	2025-05-09
2024-12-31	$3,108,472	197,740	+24.8%	Shares	Sole	2025-02-12
2024-09-30	$3,340,378	158,462	+0.8%	Shares	Sole	2024-11-12
2024-06-30	$2,618,768	157,189	+8.5%	Shares	Sole	2024-08-12
2024-03-31	$2,076,273	144,890	-0.1%	Shares	Sole	2024-05-09
2023-12-31	$2,090,741	144,989	-25.8%	Shares	Sole	2024-02-12
2023-09-30	$2,143,362	195,384	-4.8%	Shares	Sole	2023-11-09
2023-06-30	$2,556,268	205,158	-1.7%	Shares	Sole	2023-08-11
2023-03-31	$3,113,013	208,647	—	Shares	Sole	2023-05-12
No filing history on record for this holder in this stock.