SEC 13F Intelligence

Managers / Q1 2026

Mountaineer Partners Management, LLC

CIK 0001730532 · 950 3RD AVENUE, 28TH FLOOR, NEW YORK, NY, 10022 · 646-459-7060

Reported Value
$201M
Q1 2026
Positions
32
Filings on Record
31
2019–present window
Filed
May 15, 2026
original filing

Summary

Mountaineer Partners Management, LLC reported $201M in U.S.-listed holdings across 32 positions for Q1 2026.

Its largest position, CENX, represents 15.8% of the portfolio.

Compared with Q4 2025, the fund opened 1 new position and exited 2.

Portfolio Metrics

Turnover
+7.6%
vs prior filed quarter
Top-10 Concentration
+67.8%
share of reported value
Largest Position
+15.8%
Century Alum
New / Exited
1 / 2
positions this quarter

Methodology: turnover is min(value bought, value sold) ÷ average reported value across the two quarters — value-based, so market moves inflate it slightly versus a share-based measure. Concentration and largest position are shares of the filing’s total reported value, options excluded. New/exited counts compare against the prior filed quarter. All figures derive solely from the fund’s 13F filings.

Reported Value by Quarter

13F Reported Value
Q4 ’18: $118MQ4 ’18Q1 ’19: $117MQ2 ’19: $217MQ3 ’19: $99MQ4 ’19: $90MQ4 ’19Q1 ’20: $70MQ2 ’20: $74MQ3 ’20: $116MQ4 ’20: $139MQ4 ’20Q1 ’21: $143MQ2 ’21: $137MQ3 ’21: $153MQ4 ’21: $184MQ4 ’21Q1 ’22: $182MQ2 ’22: $99MQ3 ’22: $79MQ4 ’22: $105MQ4 ’22Q1 ’23: $138MQ2 ’23: $181MQ3 ’23: $156MQ4 ’23: $197MQ4 ’23Q1 ’24: $217MQ2 ’24: $192MQ3 ’24: $160MQ4 ’24: $137MQ4 ’24Q1 ’25: $105MQ2 ’25: $151MQ3 ’25: $172MQ4 ’25: $179MQ4 ’25Q1 ’26: $201Mfilingsflow.com

Portfolio Composition

By security type
Common Stock: 83.1%Other: 11.8%ADR: 5.1%
  • Common Stock · 83.1% · $167M
  • Other · 11.8% · $24M
  • ADR · 5.1% · $10M

Quarter-over-Quarter Changes full breakdown →

vs Q4 2025 (amended baseline)

IssuerMoveShare ΔShares nowValue ΔValue now
HAMHARMONY GOLD MNG LTDNEW+666.7K666.7K+$10M$10M
NXENEXGEN ENERGY LTDSOLD OUT538.0K0$5M$0
SJTSAN JUAN BASIN RTY TRSOLD OUT732.4K0$4M$0
SSFSENSIENT TECHNOLOGIES CORPADDED+39.5K156.6K+$3M$14M
ATDATI INCTRIMMED37.1K91.8K$1M$13M
ARDAGH METAL PACKAGING S AADDED+408.6K1.88M+$2M$8M
SAROSTANDARDAERO INCADDED+39.9K407.4K$15,797$11M
HBMHUDBAY MINERALS INCTRIMMED81.2K706.0K$870,616$15M

Value changes conflate price moves with buying and selling — share changes are the real signal. Share counts are not split-adjusted.

Holdings — Q1 2026

16 positions
#IssuerClass% PortfolioValueShares
1CENXCENTURY ALUM COhistory →COM17.02%$34M584.0K
2CONSTELLIUM SECL A SHS8.04%$16M658.5K
3AAALCOA CORPhistory →COM7.70%$16M233.7K
4HBMHUDBAY MINERALS INChistory →COM7.33%$15M706.0K
5FCXFREEPORT MCMORAN INChistory →CL B7.04%$14M241.0K
6CRSCARPENTER TECHNOLOGY CORPhistory →COM7.03%$14M35.9K
7SSFSENSIENT TECHNOLOGIES CORPhistory →COM6.72%$14M156.6K
8ATDATI INChistory →COM6.63%$13M91.8K
9KEXKIRBY CORPhistory →COM5.88%$12M89.0K
10SAROSTANDARDAERO INChistory →COM5.23%$11M407.4K
11HAMHARMONY GOLD MNG LTDhistory →SPONSORED ADR5.09%$10M666.7K
12DHID R HORTON INChistory →COM4.54%$9M66.5K
13BLDRBUILDERS FIRSTSOURCE INChistory →COM4.02%$8M98.2K
14ARDAGH METAL PACKAGING S ASHS3.78%$8M1.88M
15CCOCAMECO CORPhistory →COM2.29%$5M42.4K
16ULCCFRONTIER GROUP HLDGS INChistory →COM1.67%$3M953.4K

Filing History

QuarterReported ValuePositionsFiledTypeLinks
Q1 2026$201M32May 15, 202613F-HRchanges · EDGAR ↗
Q4 2025$179M34Feb 13, 202613F-HRchanges · EDGAR ↗
Q3 2025$172M36Nov 14, 202513F-HRchanges · EDGAR ↗
Q2 2025$151M32Aug 14, 202513F-HRchanges · EDGAR ↗
Q1 2025$105M28May 15, 202513F-HRchanges · EDGAR ↗
Q4 2024$137M34Feb 14, 202513F-HRchanges · EDGAR ↗
Q3 2024$160M30Nov 15, 2024RESTATEMENTchanges · EDGAR ↗
Q2 2024$192M32Aug 14, 202413F-HRchanges · EDGAR ↗
Q1 2024$217M32May 15, 202413F-HRchanges · EDGAR ↗
Q4 2023$197M28Feb 14, 202413F-HRchanges · EDGAR ↗
Q3 2023$156M28Nov 14, 202313F-HRchanges · EDGAR ↗
Q2 2023$181M28Aug 14, 202313F-HRchanges · EDGAR ↗
Q1 2023$138M26May 15, 202313F-HRchanges · EDGAR ↗
Q4 2022$105M18Feb 14, 202313F-HRchanges · EDGAR ↗
Q3 2022$79M18Nov 14, 202213F-HRchanges · EDGAR ↗
Q2 2022$99M20Aug 15, 202213F-HRchanges · EDGAR ↗
Q1 2022$182M30May 16, 202213F-HRchanges · EDGAR ↗
Q4 2021$184M34Feb 14, 202213F-HRchanges · EDGAR ↗
Q3 2021$153M32Nov 15, 202113F-HRchanges · EDGAR ↗
Q2 2021$137M28Aug 16, 202113F-HRchanges · EDGAR ↗
Q1 2021$143M30May 14, 202113F-HRchanges · EDGAR ↗
Q4 2020$139M34Feb 12, 202113F-HRchanges · EDGAR ↗
Q3 2020$116M31Nov 13, 202013F-HRchanges · EDGAR ↗
Q2 2020$74M25Aug 13, 202013F-HRchanges · EDGAR ↗
Q1 2020$70M31May 14, 202013F-HRchanges · EDGAR ↗
Q4 2019$90M25Feb 13, 202013F-HRchanges · EDGAR ↗
Q3 2019$99M25Nov 13, 201913F-HRchanges · EDGAR ↗
Q2 2019$217M27Aug 13, 201913F-HRchanges · EDGAR ↗
Q1 2019$117M26May 14, 201913F-HRchanges · EDGAR ↗
Q4 2018$118M28Feb 14, 201913F-HRchanges · EDGAR ↗

13F filings are due up to 45 days after quarter end, so holdings shown here lag the fund’s current book. Source: original SEC filing on EDGAR ↗.