Mad River Investors 13F holdings
Mad River Investors reported 29 positions with a total reported value of $267.4M as of 2026-06-30, in its 13F for Q2 2026, filed 2026-08-03. Top holdings by reported value: TPL TEXAS PACIFIC LAND CORPORATI (46.7%), PBT PERMIAN BASIN RTY TR (9.4%), LB LANDBRIDGE COMPANY LLC (7.9%), HAWAIIAN ELEC INDS INC MTN B (6.7%), GBTC GRAYSCALE BITCOIN TRUST ETF (6.1%). Against 2026-03-31 it opened 1 new position and exited 3. Next 13F due by 2026-11-14, the legal deadline 45 days after the quarter ending 2026-09-30.
Email me when Mad River Investors files its 13F
A free account follows up to 10 funds. New 13F filings arrive in your daily or weekly digest. No password and no card.
Top holdings
25 largest of 29 positions · reported value as of 2026-06-30
| Holding | Shares | Reported value | % of portfolio |
|---|---|---|---|
| TPL TEXAS PACIFIC LAND CORPORATI | 285,330 | $124.9M | 46.7% |
| PBT PERMIAN BASIN RTY TR | 1,005,152 | $25.2M | 9.4% |
| LB LANDBRIDGE COMPANY LLC | 267,953 | $21.2M | 7.9% |
| HAWAIIAN ELEC INDS INC MTN B | 1,321,850 | $17.9M | 6.7% |
| GBTC GRAYSCALE BITCOIN TRUST ETF | 360,139 | $16.4M | 6.1% |
| MIAMI INTL HLDGS INC | 289,000 | $10.7M | 4.0% |
| WBI WATERBRIDGE INFRASTRUCTURE L | 267,801 | $9.2M | 3.4% |
| MSB MESABI TR | 323,735 | $8.2M | 3.1% |
| WPM WHEATON PRECIOUS METALS CORP | 56,173 | $6.3M | 2.4% |
| FNV FRANCO NEV CORP | 22,506 | $4.7M | 1.8% |
| FBTC FIDELITY WISE ORIGIN BITCOIN | 70,369 | $3.6M | 1.3% |
| CCL CARNIVAL CORP LTD | 95,373 | $2.7M | 1.0% |
| VANGUARD INDEX FDS | 6,800 | $2.5M | 0.9% |
| BTC GRAYSCALE BITCOIN MINI TR ET | 81,517 | $2.1M | 0.8% |
| PANW PALO ALTO NETWORKS INC | 5,484 | $1.9M | 0.7% |
| CBOE CBOE GLOBAL MKTS INC | 6,705 | $1.6M | 0.6% |
| AAPL APPLE INC | 5,050 | $1.5M | 0.5% |
| ORCL ORACLE CORP | 8,050 | $1.2M | 0.4% |
| ICE INTERCONTINENTAL EXCHANGE IN | 7,846 | $965.9K | 0.4% |
| AMZN AMAZON COM INC | 3,400 | $810.4K | 0.3% |
| UNH UNITEDHEALTH GROUP INC | 1,700 | $706.6K | 0.3% |
| CSCO CISCO SYS INC | 6,000 | $704.8K | 0.3% |
| CINCINNATI FINL CORP | 3,600 | $666.5K | 0.2% |
| ETN EATON CORP PLC | 1,200 | $511.3K | 0.2% |
| RLI RLI CORP | 6,000 | $354.4K | 0.1% |
SEC FORM 13F · Q2 2026 · VALUES AS REPORTED, NOT PRICES
New positions this quarter
Held at 2026-06-30, not at 2026-03-31 · 1 in all · reported value as of 2026-06-30
| Holding | Shares | Reported value | % of portfolio |
|---|---|---|---|
| FRMI FERMI INC | 16,500 | $151.1K | <0.1% |
Sold out
Held at 2026-03-31, gone by 2026-06-30 · 3 in all · reported value as of 2026-03-31
Biggest increases and decreases
Positions held at both quarter ends, by change in shares · reported value as of 2026-06-30
Increases
| Holding | Shares 2026-03-31 | Shares 2026-06-30 | Change | Reported value |
|---|---|---|---|---|
| MIAMI INTL HLDGS INC | 81,250 | 289,000 | +255.7% | $10.7M |
| LB LANDBRIDGE COMPANY LLC | 266,385 | 267,953 | +0.6% | $21.2M |
| TPL TEXAS PACIFIC LAND CORPORATI | 285,120 | 285,330 | +0.1% | $124.9M |
| HAWAIIAN ELEC INDS INC MTN B | 1,317,050 | 1,321,850 | +0.4% | $17.9M |
| MSB MESABI TR | 321,546 | 323,735 | +0.7% | $8.2M |
| PBT PERMIAN BASIN RTY TR | 1,003,140 | 1,005,152 | +0.2% | $25.2M |
| ICE INTERCONTINENTAL EXCHANGE IN | 7,645 | 7,846 | +2.6% | $965.9K |
| BTC GRAYSCALE BITCOIN MINI TR ET | 81,217 | 81,517 | +0.4% | $2.1M |
| CBOE CBOE GLOBAL MKTS INC | 6,680 | 6,705 | +0.4% | $1.6M |
| FBTC FIDELITY WISE ORIGIN BITCOIN | 70,339 | 70,369 | +0.0% | $3.6M |
Decreases
| Holding | Shares 2026-03-31 | Shares 2026-06-30 | Change | Reported value |
|---|---|---|---|---|
| WPM WHEATON PRECIOUS METALS CORP | 89,271 | 56,173 | -37.1% | $6.3M |
| CCL CARNIVAL CORP LTD | 156,181 | 95,373 | -38.9% | $2.7M |
| VANGUARD INDEX FDS | 8,800 | 6,800 | -22.7% | $2.5M |
| FNV FRANCO NEV CORP | 23,590 | 22,506 | -4.6% | $4.7M |
| CACI INTL INC | 805 | 455 | -43.5% | $210.8K |
| WBI WATERBRIDGE INFRASTRUCTURE L | 270,900 | 267,801 | -1.1% | $9.2M |
| BRK-B BERKSHIRE HATHAWAY INC DEL | 825 | 625 | -24.2% | $312.7K |
| AMZN AMAZON COM INC | 3,500 | 3,400 | -2.9% | $810.4K |
| AAPL APPLE INC | 5,100 | 5,050 | -1.0% | $1.5M |
CIK 1384484 · 13F FILINGS ON EDGAR · INFORMATIONAL ONLY
