Institutional Manager · CIK 0001730532
Mountaineer Partners Management, LLC
New York, NY · File #028-19269
Latest AUM
$178.7M
Positions
34
Top-10 Concentration
65.0%
Filings
10
Portfolio Value Over Time
2024-03
2024-06
2024-09
2024-12
2025-03
2025-06
2025-09
2025-12
Biggest QoQ Changes
Ranked by conviction flow (share change × current price) so mark-to-market moves don't dominate. Price effect column shows how much of the $ change was just the stock moving.
| Action | Issuer | Ticker / CUSIP | Δ Shares | Flow ($) | Price Effect |
|---|---|---|---|---|---|
| EXITED | EVERUS CONSTR GROUP | 300426103 | -145,006 | -$12.4M | $0 |
| ADD | ATI INC | ATI | +84,971 | +$9.8M | +$870,290 |
| EXITED | VISHAY INTERTECHNOLOGY INC | 928298108 | -614,208 | -$9.4M | $0 |
| EXITED | ENTEGRIS INC | 29362U104 | -101,490 | -$9.4M | $0 |
| NEW | SENSIENT TECHNOLOGIES CORP | SXT | +96,411 | +$9.1M | $0 |
| ADD | FREEPORT-MCMORAN INC | FCX | +171,719 | +$8.7M | +$625,729 |
| ADD | CONSTELLIUM SE | CSTM | +436,617 | +$8.2M | +$534,394 |
| REDUCE | CARPENTER TECHNOLOGY CORP | CRS | -25,993 | -$8.2M | +$2.2M |
| ADD | ALCOA CORP | AA | +142,444 | +$7.6M | +$1.2M |
| ADD | BUILDERS FIRSTSOURCE INC | BLDR | +62,123 | +$6.4M | -$248,062 |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 202534 pos · $178.7M
- 13F HOLDINGS REPORTQ/E Sep 202536 pos · $171.9M
- 13F HOLDINGS REPORTQ/E Jun 202532 pos · $151.3M
- 13F HOLDINGS REPORTQ/E Mar 202528 pos · $104.5M
- 13F HOLDINGS REPORTQ/E Dec 202434 pos · $136.6M
- 13F HOLDINGS REPORT (Amended)Q/E Sep 202430 pos · $160.4M
- 13F HOLDINGS REPORTQ/E Sep 202430 pos · $6.6M
- 13F HOLDINGS REPORTQ/E Jun 202432 pos · $192.2M
- 13F HOLDINGS REPORTQ/E Mar 202432 pos · $216.6M
- 13F HOLDINGS REPORTQ/E Dec 202328 pos · $156.0M
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | CENTURY ALUM CO | CENX | 555,380 | $21.8M | 12.18% |
| 2 | HUDBAY MINERALS INC | HBM | 683,481 | $13.6M | 7.59% |
| 3 | ATI INC | ATI | 111,012 | $12.7M | 7.13% |
| 4 | FREEPORT-MCMORAN INC | FCX | 225,801 | $11.5M | 6.42% |
| 5 | ALCOA CORP | AA | 203,791 | $10.8M | 6.06% |
| 6 | CONSTELLIUM SE | CSTM | 571,225 | $10.8M | 6.02% |
| 7 | CARPENTER TECHNOLOGY CORP | CRS | 30,388 | $9.6M | 5.35% |
| 8 | SENSIENT TECHNOLOGIES CORP | SXT | 96,411 | $9.1M | 5.07% |
| 9 | STANDARDAERO INC | SARO | 298,025 | $8.5M | 4.78% |
| 10 | BUILDERS FIRSTSOURCE INC | BLDR | 75,634 | $7.8M | 4.35% |
| 11 | KIRBY CORP | KEX | 69,748 | $7.7M | 4.30% |
| 12 | D R HORTON INC | 23331A109 | 52,048 | $7.5M | 4.19% |
| 13 | ARDAGH METAL PACKAGING S A | AMPWF | 1,102,670 | $4.5M | 2.53% |
| 14 | NEXGEN ENERGY LTD | NXE | 408,571 | $3.8M | 2.10% |
| 15 | FRONTIER GROUP HLDGS INC | ULCC | 747,181 | $3.5M | 1.97% |
| 16 | SAN JUAN BASIN RTY TR | 798241105 | 563,924 | $3.2M | 1.77% |
| 17 | CAMECO CORP | CCJ | 33,307 | $3.0M | 1.70% |
| 18 | CENTURY ALUM CO | CENX | 53,095 | $2.1M | 1.16% |
| 19 | CONSTELLIUM SE | CSTM | 110,239 | $2.1M | 1.16% |
| 20 | HUDBAY MINERALS INC | HBM | 103,766 | $2.1M | 1.15% |