Mountaineer Partners Management, LLC

New York, NY · CIK 1730532 · 13F filing filed 2026-08-13

SEC-registered investment adviser since 2013 · limited liability company

Assets managed$305.7m
Staff4 · 3 in investment roles
Main clients (by assets)Charities 49%, Private funds 32%, Mutual funds and ETFs 19%
Private funds3 (3 hedge) · $175.5m gross assets
Websitemountaineerpartners.com
Form ADV · 2026-03-31SEC adviser record

As an employer

$137.5m reported value -31.7% vs Q1 2026

11positions

97.0%in top 10

1 new 1 added 9 reduced 6 sold out vs Q1 2026

The small lines show how much was held over the last 4 quarters (adjusted for stock splits).

#	Security	Ticker	Shares	Value	% of portfolio	Change	Shares change
1	CENTURY ALUM CO COM CENX	CENX	503,309	$23.2m16.84%	16.84%	Reduced -80.7k	-80,688 -13.8%
2	SENSIENT TECHNOLOGIES CORP COM SXT	SXT	131,727	$16.2m11.81%	11.81%	Reduced -24.9k	-24,857 -15.9%
3	CONSTELLIUM SE CL A SHS CSTM	CSTM	482,130	$15.4m11.18%	11.18%	Reduced -176.4k	-176,360 -26.8%
4	STANDARDAERO INC COM SARO	SARO	464,595	$13.9m10.11%	10.11%	Added +57.2k	+57,160 14.0%
5	CARPENTER TECHNOLOGY CORP COM CRS	CRS	20,894	$12.9m9.37%	9.37%	Reduced -15.0k	-15,035 -41.9%
6	ATI INC COM ATI	ATI	60,419	$11.9m8.66%	8.66%	Reduced -31.4k	-31,365 -34.2%
7	MIDDLEBY CORP COM MIDD	MIDD	67,536	$11.6m8.45%	8.45%	New
8	ALCOA CORP COM AA	AA	208,165	$10.9m7.89%	7.89%	Reduced -25.5k	-25,522 -10.9%
9	HARMONY GOLD MINING CO LTD SPONSORED ADR HMY	HMY	612,949	$9.3m6.78%	6.78%	Reduced -53.8k	-53,786 -8.1%
10	ARDAGH METAL PACKAGING S A SHS AMBP	AMBP	1,722,234	$8.2m5.94%	5.94%	Reduced -155.8k	-155,848 -8.3%
11	CAMECO CORP COM CCJ	CCJ	39,903	$4.1m2.96%	2.96%	Reduced -2.5k	-2,521 -5.9%

Security	Ticker	Shares held before	Value then
HUDBAY MINERALS INC HBM	HBM	706,040	$14.8m706.0k shares
FREEPORT-MCMORAN INC FCX	FCX	240,973	$14.2m241.0k shares
KIRBY CORP KEX	KEX	89,017	$11.8m89.0k shares
D R HORTON INC DHI	DHI	66,541	$9.1m66.5k shares
BUILDERS FIRSTSOURCE INC BLDR	BLDR	98,203	$8.1m98.2k shares
FRONTIER GROUP HLDGS INC ULCC	ULCC	953,375	$3.4m953.4k shares