Q2 2026 13F · SEC CIK 1730532
Mountaineer Partners Management, LLC
Hedge fundFiled 2026-08-13 for Q2 2026. Open the filing ↗ · All SEC filings ↗
- Reported 13F value
- $132.0M
- Reported positions
- 11
- Top holdings a year, 3 yrs
- +26.7%
- Assets under management
- $305.7M
Mountaineer Partners Management, LLC is a hedge fund that reported 11 positions worth $132.0M in its Q2 2026 13F, filed 2026-08-13. Its largest holdings were Century Alum Co (CENX, 17.5%), Sensient Technologies Corp (SXT, 12.3%), Constellium SE (CSTM, 11.6%). A portfolio copying its top holdings returned 26.7% a year over the last 3 years, against 20.4% for the S&P 500.
Mountaineer Partners Management, LLC holdings all 11 positions.
Weights are shares of the filer's total reported 13F value, compared with Q1 2026. Share changes may reflect splits; weight changes also reflect price moves. A 13F shows long US-listed positions only, up to 135 days after the fact.
| Stock | % of 13F value | Share change | Reported value |
|---|---|---|---|
| CENXCentury Alum Co | 17.5% | -13.8% | $23.2M |
| SXTSensient Technologies Corp | 12.3% | -15.9% | $16.2M |
| CSTMConstellium SE | 11.6% | -26.8% | $15.4M |
| SAROStandardaero Inc | 10.5% | +14.0% | $13.9M |
| CRSCarpenter Technology Corp | 9.8% | -41.8% | $12.9M |
| ATIAti Inc | 9.0% | -34.2% | $11.9M |
| MIDDMiddleby Corp | 8.8% | — | $11.6M |
| AAAlcoa Corp Com | 8.2% | -10.9% | $10.9M |
| HMYHarmony Gold Mng Ltd | 7.1% | -8.1% | $9.3M |
| CCJCameco Corp | 3.1% | -5.9% | $4.1M |
| AMBPArdagh Metal Packaging S A | 2.1% | -69.4% | $2.7M |
What Mountaineer Partners Management, LLC bought and sold in Q2 2026, against Q1 2026.
New positions
- MIDD Middleby Corp8.8% of 13F
Added to
- SARO Standardaero Inc+14.0% shares
Reduced
- AMBP Ardagh Metal Packaging S A-69.4% shares
- CRS Carpenter Technology Corp-41.8% shares
- ATI Ati Inc-34.2% shares
- CSTM Constellium SE-26.8% shares
- SXT Sensient Technologies Corp-15.9% shares
- CENX Century Alum Co-13.8% shares
- AA Alcoa Corp Com-10.9% shares
- HMY Harmony Gold Mng Ltd-8.1% shares
Sold out
- HBM Hudbay Minerals Incwas 7.3%
- FCX Freeport Mcmoran Incwas 7.0%
- KEX Kirby Corpwas 5.9%
- DHI D R Horton Incwas 4.5%
- BLDR Builders Firstsource Incwas 4.0%
- ULCC Frontier Group Hldgs Incwas 1.7%
Share counts compared with the Q1 2026 13F; a split also changes share counts.
How the holdings did against the S&P 500.
- 1 year
- +74.5% /yr
- S&P 500 +20.1%
- 3 years
- +26.7% /yr
- S&P 500 +20.4%
- 5 years
- +15.3% /yr
- S&P 500 +11.6%
A portfolio of the filer's 20 largest 13F positions, weighted by value, bought the trading day after each 13F was filed and held until the next one was: what copying this filer could have earned. 13Fs show long US-listed positions only, so this is an estimate of the stock picks, not the fund's reported returns.
Reported 13F value by quarter.
| Quarter | 13F value | Positions |
|---|---|---|
| Q2 2026 | $132.0M | 11 |
| Q1 2026 | $201.3M | 16 |
| Q4 2025 | $178.7M | 17 |
| Q3 2025 | $171.9M | 18 |
| Q2 2025 | $151.3M | 16 |
| Q1 2025 | $104.5M | 14 |
| Q4 2024 | $136.6M | 17 |
| Q3 2024 | $160.4M | 15 |
| Q2 2024 | $192.2M | 16 |
| Q1 2024 | $216.6M | 16 |
| Q4 2023 | $196.8M | 14 |
| Q3 2023 | $156.0M | 14 |
Questions about Mountaineer Partners Management, LLC's portfolio
What stocks does Mountaineer Partners Management, LLC own?
Mountaineer Partners Management, LLC's latest 13F, for Q2 2026 and filed Aug 13, 2026, lists 11 positions worth $132.0M. The largest are Century Alum Co (CENX) at 17.5%, Sensient Technologies Corp (SXT) at 12.3%, Constellium SE (CSTM) at 11.6%, Standardaero Inc (SARO) at 10.5% and Carpenter Technology Corp (CRS) at 9.8%.
What did Mountaineer Partners Management, LLC buy last quarter?
In Q2 2026, Mountaineer Partners Management, LLC added a new position in Middleby Corp (MIDD) and Standardaero Inc (SARO) (+14.0% shares), compared with its Q1 2026 filing.
What did Mountaineer Partners Management, LLC sell last quarter?
In Q2 2026, Mountaineer Partners Management, LLC sold all of Hudbay Minerals Inc (HBM), sold all of Freeport Mcmoran Inc (FCX), sold all of Kirby Corp (KEX), sold all of D R Horton Inc (DHI), sold all of Builders Firstsource Inc (BLDR), Ardagh Metal Packaging S A (AMBP) (-69.4% shares), Carpenter Technology Corp (CRS) (-41.8% shares) and Ati Inc (ATI) (-34.2% shares), compared with its Q1 2026 filing.
How has Mountaineer Partners Management, LLC's portfolio performed?
A portfolio copying Mountaineer Partners Management, LLC's 20 largest 13F holdings each quarter, from the day each filing was public, returned +26.7% a year over the last 3 years, against +20.4% for the S&P 500. Over 1 year: +74.5% against +20.1%. Over 5 years: +15.3% a year against +11.6%.
When is Mountaineer Partners Management, LLC's next 13F filing due?
13F filings are due 45 days after each quarter ends. Mountaineer Partners Management, LLC's filing for the quarter ending Sep 30, 2026 is due by Nov 14, 2026; this page updates the day after it is published.
How much money does Mountaineer Partners Management, LLC manage?
Mountaineer Partners Management, LLC reported $305.7M of regulatory assets under management on its latest SEC Form ADV. Its 13F, which covers only US-listed stocks and options, totals $132.0M.