MAD RIVER INVESTORS — 13F Holdings & Portfolio
CIK 1384484 · latest 13F-HR filed 2026-08-03
MAD RIVER INVESTORS manages $268.1M in 13F-reported U.S. long-equity assets across 30 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are TPL (46.58%), PBT (9.39%), LB (7.92%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 2 new positions and exited 4; 11 existing positions rose in reported value and 13 fell.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
Long-equity book
Distinct positions
Filed 2026-08-03
vs 2026-03-31
Portfolio charts
Latest quarter's book, what changed, and how the portfolio has evolved across filings.
Portfolio map
Q2 26Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.
Sector mix
% of 13F valueSectors from each company's SIC code; funds and ETFs grouped separately.
Biggest buys and sells
Q1 26 → Q2 26Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.
13F assets and positions
3 quartersTotal reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.
Top positions over time
reported valueThe eight largest current positions, valued at each quarter end.
Concentration
top 10 = 91.5%Cumulative share of the portfolio held in the largest N positions.
| Name | Title / Status | Ownership | Type |
|---|
Quarter-over-quarter changes
Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.
Top Adds (vs prior quarter)
- MIAMI INTL HLDGS INC$7.6M +239.6%
- PERMIAN BASIN RTY TR$3.6M +16.6%
- LANDBRIDGE COMPANY LLC$2.8M +15.4%
- WATERBRIDGE INFRASTRUCTURE L$1.9M +26.5%
- PALO ALTO NETWORKS INC$991.0K +112.7%
Top Trims
- TEXAS PACIFIC LAND CORPORATI-$10.4M -7.7%
- WHEATON PRECIOUS METALS CORP-$5.4M -46.1%
- GRAYSCALE BITCOIN TRUST ETF-$2.6M -13.7%
- MESABI TR-$1.9M -19.1%
- HAWAIIAN ELEC INDS INC MTN B-$1.7M -8.5%
Exited Positions
- CARNIVAL CORP$4.0M
- ROYAL GOLD INC$626.8K
- JPMORGAN CHASE & CO$416.8K
- VANGUARD SPECIALIZED FUNDS$215.1K
MAD RIVER INVESTORS Holdings (2026-06-30)
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | TEXAS PACIFIC LAND CORPORATI | TPL | 88262P102 | $124.9M | 46.58% | 285,330 | SH |
| 2 | PERMIAN BASIN RTY TR | PBT | 714236106 | $25.2M | 9.39% | 1,005,152 | SH |
| 3 | LANDBRIDGE COMPANY LLC | LB | 514952100 | $21.2M | 7.92% | 267,953 | SH |
| 4 | HAWAIIAN ELEC INDS INC MTN B | HE | 419870100 | $17.9M | 6.67% | 1,321,850 | SH |
| 5 | GRAYSCALE BITCOIN TRUST ETF | GBTC | 389637109 | $16.4M | 6.11% | 360,139 | SH |
| 6 | MIAMI INTL HLDGS INC | MIAX | 59356Q108 | $10.7M | 4.01% | 289,000 | SH |
| 7 | WATERBRIDGE INFRASTRUCTURE L | WBI | 940923105 | $9.2M | 3.42% | 267,801 | SH |
| 8 | MESABI TR | MSB | 590672101 | $8.2M | 3.05% | 323,735 | SH |
| 9 | WHEATON PRECIOUS METALS CORP | WPM | 962879102 | $6.3M | 2.35% | 56,173 | SH |
| 10 | FRANCO NEV CORP | FNV | 351858105 | $4.7M | 1.75% | 22,506 | SH |
| 11 | FIDELITY WISE ORIGIN BITCOIN | FBTC | 315948109 | $3.6M | 1.34% | 70,369 | SH |
| 12 | CARNIVAL CORP LTD | CCL | G2004J103 | $2.7M | 1.02% | 95,373 | SH |
| 13 | VANGUARD INDEX FDS | VTI | 922908769 | $2.5M | 0.94% | 6,800 | SH |
| 14 | GRAYSCALE BITCOIN MINI TR ET | BTC | 389930207 | $2.1M | 0.79% | 81,517 | SH |
| 15 | PALO ALTO NETWORKS INC | PANW | 697435105 | $1.9M | 0.70% | 5,484 | SH |
| 16 | CBOE GLOBAL MKTS INC | CBOE | 12503M108 | $1.6M | 0.61% | 6,705 | SH |
| 17 | APPLE INC | AAPL | 037833100 | $1.5M | 0.55% | 5,050 | SH |
| 18 | ORACLE CORP | ORCL | 68389X105 | $1.2M | 0.44% | 8,050 | SH |
| 19 | INTERCONTINENTAL EXCHANGE IN | ICE | 45866F104 | $965.9K | 0.36% | 7,846 | SH |
| 20 | AMAZON COM INC | AMZN | 023135106 | $810.4K | 0.30% | 3,400 | SH |
| 21 | UNITEDHEALTH GROUP INC | UNH | 91324P102 | $706.6K | 0.26% | 1,700 | SH |
| 22 | CISCO SYS INC | CSCO | 17275R102 | $704.8K | 0.26% | 6,000 | SH |
| 23 | CINCINNATI FINL CORP | CINF | 172062101 | $666.5K | 0.25% | 3,600 | SH |
| 24 | HAWAIIAN ELEC INDS INC MTN B Call | HE | 419870100 | $660.3K | 0.25% | 48,800 | PRN |
| 25 | EATON CORP PLC | ETN | G29183103 | $511.3K | 0.19% | 1,200 | SH |
| 26 | RLI CORP | RLI | 749607107 | $354.4K | 0.13% | 6,000 | SH |
| 27 | BERKSHIRE HATHAWAY INC DEL | BRK.B | 084670702 | $312.7K | 0.12% | 625 | SH |
| 28 | JOHNSON & JOHNSON | JNJ | 478160104 | $304.8K | 0.11% | 1,200 | SH |
| 29 | CACI INTL INC | CACI | 127190304 | $210.8K | 0.08% | 455 | SH |
| 30 | FERMI INC | FRMI | 314911108 | $151.1K | 0.06% | 16,500 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-03 | $268.1M | 30 | 0001384484-26-000006 |
| 2026-03-31 | 2026-04-23 | $277.9M | 32 | 0001384484-26-000004 |
| 2025-12-31 | 2026-02-06 | $219.6M | 35 | 0001384484-26-000002 |
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