Boundary Creek Advisors LP In its 13F for Q2 2025 (holdings as of June 30, 2025, filed August 12, 2025), Boundary Creek Advisors LP reported 3 stock positions worth $39.9 million . Its top holding was Solaris Resources (SLSR) at 57.1% of the portfolio, followed by Mativ (MATV, 22.4% ) and Mercer International (MERC, 20.5% ). Compared with Q1 2025, it sold out of 8 and reduced 3. The biggest sale was an exit from Knight-Swift Transportation (KNX).
Location TUCKAHOE, NY
CIK 0001771944
Portfolio Value $39.9M (Q2 2025) Holdings 3 stocks · $39.9M Holdings quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock % Of Portfolio ▼ Shares Held Total Value Change vs Q1 2025 SLSR Solaris Resources Inc. 4,976,710 $22.8M Reduce -32.9% MATV Mativ Holdings Inc. 1,313,984 $9.0M Reduce -32.5% MERC Mercer International Inc. 2,333,375 $8.2M Reduce -41.4%
Options reported separately and not counted above: SPY calls ($308.9M), MPT puts ($97.0M), MATV calls ($6.0M), MERC calls ($4.9M).
Other holdings (1): bonds, preferreds, convertibles and warrants · $4K (not counted above) Security Class Shares / Principal Value Change VEEAW Plum Acquisition I A -CW28 *W EXP 09/13/202 28,083 $4K No change
Total filed on the 13F, all lines: $39.9M.
Portfolio Sells Q1 2025 → Q2 2025 Portfolio Sells quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock Change vs Q1 2025 % Of Portfolio Change To Portfolio ▲ KNX Knight-Swift Transportation Sold out 0.00% −14.23 LEU Centrus Energy Corp. Class A Sold out 0.00% −9.86 CEG Constellation Energy Sold out 0.00% −5.06 VLO Valero Energy Corp. Sold out 0.00% −4.82 VST Vistra Corp. Sold out 0.00% −4.28 UIS Unisys Corp. Sold out 0.00% −2.80 EU Encore Energy Corp. Sold out 0.00% −2.64 MERC Mercer International Inc. Reduce -41.4% 20.45% −1.88 URBAN ONE INC Sold out 0.00% −0.18 MATV Mativ Holdings Inc. Reduce -32.5% 22.44% +11.39 SLSR Solaris Resources Inc. Reduce -32.9% 57.10% +34.35
Portfolio Buys Q1 2025 → Q2 2025 Portfolio Buys quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock Change vs Q1 2025 % Of Portfolio Change To Portfolio ▼ None this quarter.
Options Activity Q1 2025 → Q2 2025 Security Type Change vs Q1 2025 Underlying Shares Value ▼ SPY SS SPDR S&P 500 ETF Trust-US call New 500,000 $308.9M MPT Medical Properties Trust Inc. put Reduce -0.9% 22,500,000 $97.0M KNX Knight-Swift Transportation call Sold out 1,000,000 $43.5Mbefore exit EFA iShares MSCI Eafe ETF put Sold out 500,000 $40.9Mbefore exit VLO Valero Energy Corp. call Sold out 200,000 $26.4Mbefore exit DXC DXC Technology Co. call Sold out 500,000 $8.5Mbefore exit MERC Mercer International Inc. call New 1,400,000 $4.9M SLSR Solaris Resources Inc. call Sold out 147,300 $499Kbefore exit
Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.
Notes & Other Activity Q1 2025 → Q2 2025 Security Class Change vs Q1 2025 Shares / Principal Value ▼ WOLF Wolfspeed Inc. (wolf 1.875 12/01/29) NOTE 1.875%12/0 · principal Sold out 17,500,000 $4.0Mbefore exit
Bonds, preferreds, convertibles and warrants; not part of the stock holdings or percentages above.
All Filings Quarter Positions 13F Reported Value Top Holdings Q2 2026 0 $0 Q1 2026 1 $15.3M GBTG Q4 2025 1 $20.9M GBTG Q3 2025 1 $22.9M GBTG Q2 2025 3 $39.9M SLSR, MATV, MERC Q1 2025 11 $109.7M SLSR, MERC, KNX, MATV, LEU Q4 2024 11 $149.4M MERC, MATV, KNX, SLSR, LEU Q3 2024 9 $152.7M MATV, MERC, SLSR, LEU, KNX Q2 2024 16 $203.0M MATV, MERC, KNX, AMBP, SLSR Q1 2024 11 $146.8M MATV, MERC, BRSL, AMBP, KNX