In its 13F for Q2 2026 (holdings as of June 30, 2026, filed August 3, 2026), Mad River Investors reported 29 stock positions worth $267.4 million . Its top holding was Texas Pacific Land (TPL) at 46.7% of the portfolio, followed by Permian Basin Royalty Trust (PBT, 9.4% ) and Landbridge Co. LLC-A (LB, 7.9% ). Compared with Q1 2026, it opened 1 new position, sold out of 3, added to 10 and reduced 9. The biggest buy was Miami International (MIAX, shares +256% ) and the biggest sale Wheaton Precious Metals (WPM, shares −37% ).
Location BOSTON, MA
CIK 0001384484
Portfolio Value $267.4M (Q2 2026) Holdings 29 stocks · $267.4M 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 2026 TPL Texas Pacific Land Corp. 285,330 $124.9M Add +0.1% PBT Permian Basin Royalty Trust 1,005,152 $25.2M Add +0.2% LB Landbridge Co. LLC-A 267,953 $21.2M Add +0.6% HE Hawaiian Electric Inds 1,321,850 $17.9M Add +0.4% GBTC Grayscale Bitcoin Trust ETF 360,139 $16.4M No change MIAX Miami International Holdings 289,000 $10.7M Add +255.7% WBI Waterbridge Infrastruc Class A 267,801 $9.2M Reduce -1.1% MSB Mesabi Trust 323,735 $8.2M Add +0.7% WPM Wheaton Precious Metals Corp. 56,173 $6.3M Reduce -37.1% FNV Franco-Nevada Corp. 22,506 $4.7M Reduce -4.6% FBTC Fidelity Wise Origin Bitcoin 70,369 $3.6M Add +0.0% CCL Carnival Corp. Ltd. 95,373 $2.7M Reduce -38.9% VTI VG Morningstar TS MKT ETF-US 6,800 $2.5M Reduce -22.7% BTC Grayscale Bitcoin Mini ETF 81,517 $2.1M Add +0.4% PANW Palo Alto Networks Inc. 5,484 $1.9M No change CBOE Cboe Global Markets Inc. 6,705 $1.6M Add +0.4% AAPL Apple Inc. 5,050 $1.5M Reduce -1.0% ORCL Oracle Corp. 8,050 $1.2M No change ICE Intercontinental Exchange Inc. 7,846 $966K Add +2.6% AMZN Amazon.com Inc. 3,400 $810K Reduce -2.9% UNH Unitedhealth Group Inc. 1,700 $707K No change CSCO Cisco Systems Inc. 6,000 $705K No change CINF Cincinnati Financial Corp. 3,600 $667K No change ETN Eaton Corp. PLC 1,200 $511K No change RLI Rli Corp. 6,000 $354K No change BRK.B Berkshire Hathaway Inc. Class B 625 $313K Reduce -24.2% JNJ Johnson & Johnson 1,200 $305K No change CACI Caci International Inc. Class A 455 $211K Reduce -43.5% FRMI Fermi Inc. 16,500 $151K New
Options reported separately and not counted above: HE calls ($660K).
Portfolio Sells Q1 2026 → Q2 2026 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 2026 % Of Portfolio Change To Portfolio ▲ WPM Wheaton Precious Metals Corp. Reduce -37.1% 2.36% −1.86 CCL Carnival Corp. Ltd. Reduce -38.9% 1.02% −0.44 FNV Franco-Nevada Corp. Reduce -4.6% 1.75% −0.35 RGLD Royal Gold Inc. Sold out 0.00% −0.23 JPM JPMorgan Chase & Co. Sold out 0.00% −0.15 CACI Caci International Inc. Class A Reduce -43.5% 0.08% −0.08 VTI VG Morningstar TS MKT ETF-US Reduce -22.7% 0.94% −0.08 VIG Vanguard Dividend Apprec ETF Sold out 0.00% −0.08 BRK.B Berkshire Hathaway Inc. Class B Reduce -24.2% 0.12% −0.03 AMZN Amazon.com Inc. Reduce -2.9% 0.30% +0.04 AAPL Apple Inc. Reduce -1.0% 0.55% +0.08 WBI Waterbridge Infrastruc Class A Reduce -1.1% 3.43% +0.81
Portfolio Buys Q1 2026 → Q2 2026 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 2026 % Of Portfolio Change To Portfolio ▼ MIAX Miami International Holdings Add +255.7% 4.02% +2.87 PBT Permian Basin Royalty Trust Add +0.2% 9.41% +1.62 LB Landbridge Co. LLC-A Add +0.6% 7.94% +1.30 FRMI Fermi Inc. New 0.06% +0.06 CBOE Cboe Global Markets Inc. Add +0.4% 0.61% −0.07 ICE Intercontinental Exchange Inc. Add +2.6% 0.36% −0.07 BTC Grayscale Bitcoin Mini ETF Add +0.4% 0.79% −0.09 FBTC Fidelity Wise Origin Bitcoin Add +0.0% 1.34% −0.15 HE Hawaiian Electric Inds Add +0.4% 6.69% −0.36 MSB Mesabi Trust Add +0.7% 3.06% −0.59 TPL Texas Pacific Land Corp. Add +0.1% 46.69% −2.13
Options Activity Q1 2026 → Q2 2026 Security Type Change vs Q1 2026 Underlying Shares Value ▼ HE Hawaiian Electric Inds call Add +4.0% 48,800 $660K
Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.
All Filings Quarter Positions 13F Reported Value Top Holdings Q2 2026 29 $267.4M TPL, PBT, LB, HE, GBTC Q1 2026 31 $277.2M TPL, PBT, HE, GBTC, LB Q4 2025 34 $219.4M TPL, GBTC, PBT, HE, LB Q3 2025 37 $233.4M TPL, GBTC, PBT, HE, LB Q2 2025 23 $223.2M TPL, GBTC, LB, HE, PBT Q1 2025 24 $236.0M TPL, GBTC, LB, HE, WPM Q4 2024 26 $215.2M TPL, GBTC, LB, WPM, MSB Q3 2024 26 $180.3M TPL, GBTC, LB, WPM, CACI Q2 2024 27 $149.3M TPL, GBTC, WPM, CACI, CVEO Q1 2024 27 $144.1M TPL, GBTC, WPM, CACI, CVEO