Port Capital LLC

Position in ATMU — Atmus Filtration Technologies Inc.

CIK 1729212 CHICAGO, IL

Position in ATMU

as of Mar 31, 2026 · filed May 15, 2026 Compact

Position Value

$51,585,763

+$6,075,228 QoQ

Shares Held

908,680

+3.6% QoQ

Ownership

1.11%

of shares outstanding

% of Portfolio

2.52%

of 13F equity value

Holder Rank

—

not a current holder

Holding Since

Sep 2025

3 quarters on record

Voting authority Sole 100% Shared 0% None 0%

Consumer Cyclical · as of Mar 31, 2026

Port Capital LLC holds $138,653,649 across 3 Auto Parts names. ATMU ranks #2 (37.2% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	ORLY	O Reilly Automotive Inc	942,570	$87,008,636
2	ATMU	Atmus Filtration Technologies Inc. This page	908,680	$51,585,763
3	SLDP	Solid Power, Inc.	19,750	$59,250

3 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-03-31	$51,585,763	908,680	+3.6%	Shares	Sole	2026-05-15
2025-12-31	$45,510,535	876,720	+103.7%	Shares	Sole	2026-02-17
2025-09-30	$19,409,441	430,460	—	Shares	Sole	2025-11-14
No filing history on record for this holder in this stock.