Mad River Investors reported 27 positions worth $208.10M for the quarter ended Sep 30, 2026, down 13.2% on the prior quarter. It opened 1 new position, added to 8, trimmed 8 and exited 1. Its largest holding is Texas Pacific Land Corp at 44.6% of the portfolio.
Reported 13F market value at each quarter end. A change mixes trading with price moves in the positions held.
Dollar value of shares bought and sold each quarter, at that quarter’s price. It counts trading only, not price changes.
How many positions were opened, added to, trimmed or closed each quarter.
Share of reported value in each sector at every quarter end.
| Holding | Change | Change % | Trade Value | Weight |
|---|---|---|---|---|
| FRMI Fermi Inc. | +466.7K | +2,828.5% | $1.96M | 0.978% |
| FBTC Fidelity Wise Origin Bitcoin Fund | +8,060 | +11.5% | $585.47K | 2.74% |
| MIAX Miami International Holdings, Inc. | +8,157 | +2.8% | $273.26K | 4.78% |
| AAPL Apple Inc. | +797 | +15.8% | $265.42K | 0.936% |
| RGLD Royal Gold Inc | +940 | – | $221.84K | 0.107% |
| BRK-B Berkshire Hathaway Inc | +150 | +24.0% | $74.69K | 0.185% |
| MSB Mesabi Trust | +3,581 | +1.1% | $70.15K | 3.08% |
| WBI WaterBridge Infrastructure LLC | +950 | +0.4% | $26.71K | 3.63% |
| ICE Intercontinental Exchange, Inc. | +155 | +2.0% | $23.56K | 0.585% |
| Holding | Change | Change % | Trade Value | Weight |
|---|---|---|---|---|
| CCL Carnival Corp Ltd. | -76.7K | -80.4% | $1.88M | 0.22% |
| WPM Wheaton Precious Metals Corp. | -11.1K | -19.8% | $1.49M | 2.89% |
| FNV FRANCO NEVADA Corp | -1,449 | -6.4% | $345.02K | 2.41% |
| GBTC Grayscale Bitcoin Trust ETF | -4,695 | -1.3% | $303.25K | 11.03% |
| CACI Caci International Inc | -455 | -100.0% | $210.78K | Exited |
| TPL Texas Pacific Land Corp | -559 | -0.2% | $182.14K | 44.59% |
| LB LandBridge Corp | -1,248 | -0.5% | $101.30K | 10.4% |
| HE Hawaiian Electric Industries Inc | -2,800 | -0.2% | $25.03K | 5.67% |
| CBOE Cboe Global Markets, Inc. | -25 | -0.4% | $6.88K | 0.884% |
| Holding | Shares | Trade Value | Weight |
|---|---|---|---|
| RGLD Royal Gold Inc | +940 | $221.84K | 0.107% |
| Holding | Shares Sold | Trade Value | Prior Weight |
|---|---|---|---|
| CACI Caci International Inc | -455 | $210.78K | 0.088% |
| # | Activity | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | TPL Texas Pacific Land Corp | Real Estate | 284.8K | $92.79M | 44.59% | -559 | -0.2% | Reduced | 0.41% |
| 2 | GBTC Grayscale Bitcoin Trust ETF | Financial Services | 355.4K | $22.96M | 11.03% | -4,695 | -1.3% | Reduced | 0.2% |
| 3 | LB LandBridge Corp | Real Estate | 266.7K | $21.65M | 10.4% | -1,248 | -0.5% | Reduced | 0.35% |
| 4 | HE Hawaiian Electric Industries Inc | Utilities | 1.32M | $11.79M | 5.67% | -2,800 | -0.2% | Reduced | 0.76% |
| 5 | MIAX Miami International Holdings, Inc. | Financial Services | 297.2K | $9.95M | 4.78% | +8,157 | +2.8% | Added | 0.3% |
| 6 | WBI WaterBridge Infrastructure LLC | Energy | 268.8K | $7.56M | 3.63% | +950 | +0.4% | Added | 0.22% |
| 7 | MSB Mesabi Trust | Basic Materials | 327.3K | $6.41M | 3.08% | +3,581 | +1.1% | Added | 2.49% |
| 8 | WPM Wheaton Precious Metals Corp. | Financial Services | 45.0K | $6.02M | 2.89% | -11.1K | -19.8% | Reduced | 0.01% |
| 9 | FBTC Fidelity Wise Origin Bitcoin Fund | Others | 78.4K | $5.70M | 2.74% | +8,060 | +11.5% | Added | 0.04% |
| 10 | FNV FRANCO NEVADA Corp | Financial Services | 21.1K | $5.01M | 2.41% | -1,449 | -6.4% | Reduced | 0.01% |
| 11 | BTC Grayscale Bitcoin Mini Trust ETF | Others | 81.5K | $3.01M | 1.45% | 0 | 0.0% | Unchanged | 0.07% |
| 12 | PANW Palo Alto Networks Inc | Technology | 5,484 | $2.18M | 1.05% | 0 | 0.0% | Unchanged | 0% |
| 13 | FRMI Fermi Inc. | Real Estate | 483.2K | $2.03M | 0.978% | +466.7K | +2,828.5% | Added | 0.08% |
| 14 | AAPL Apple Inc. | Technology | 5,847 | $1.95M | 0.936% | +797 | +15.8% | Added | 0% |
| 15 | CBOE Cboe Global Markets, Inc. | Financial Services | 6,680 | $1.84M | 0.884% | -25 | -0.4% | Reduced | 0.01% |
Tip. Select a row to see that position’s full history at Mad River Investors.
As of its Q3 2026 13F filing, Mad River Investors’s five largest positions were Texas Pacific Land Corp (TPL) at 44.6%, Grayscale Bitcoin Trust ETF (GBTC) at 11.0%, LandBridge Corp (LB) at 10.4%, Hawaiian Electric Industries Inc (HE) at 5.7%, Miami International Holdings, Inc. (MIAX) at 4.8% of the reported portfolio.
Mad River Investors reported a 13F portfolio worth $208.10M across 27 positions for Q3 2026. That is down 13.2% from the previous quarter.
Its largest purchases by value were Fermi Inc. ($1.96M), Fidelity Wise Origin Bitcoin Fund ($585.47K), Miami International Holdings, Inc. ($273.26K). It opened 1 new positions.
Its largest sales by value were Carnival Corp Ltd. ($1.88M), Wheaton Precious Metals Corp. ($1.49M), FRANCO NEVADA Corp ($345.02K). It exited 1 positions entirely.
From the Form 13F-HR reports Mad River Investors files with the SEC each quarter, within 45 days of quarter end. A 13F lists long positions in US-listed equities and options; it excludes short positions, cash, bonds and most non-US holdings.
13F data reflects long positions in US-listed equities and options as reported to the SEC up to 45 days after quarter end. It excludes short positions, cash, bonds and most non-US securities, so it is not a complete picture of a manager’s assets.