Mad River Investors holds a concentrated book of 29 stocks worth $267.4M as of Q2 2026 (disclosed Aug 3, 2026, a ~34-day 13F lag). This quarter they opened Carnival Corp Ltd and trimmed Waterbridge Infrastruc-CL A. Their largest long position is Texas Pacific Land Corp at 47% of the equity book. They also disclosed $660K in call options (bullish), shown separately below and excluded from the equity book.
Top-heavy: concentrated book
Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.
99% mapped to company sectors
Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.
Estimated $ traded · quarter-end prices, no cost basis
Other tracked managers holding the same core names as Mad River Investors
| Manager / fund | Shared names | Their $ in those |
|---|---|---|
| MORGAN STANLEY | 45 / 29 | $203.7B |
| OSAIC HOLDINGS, INC. | 45 / 29 | $6.4B |
| JPMORGAN CHASE & CO | 44 / 29 | $157.4B |
| ROYAL BANK OF CANADA | 44 / 29 | $57.2B |
| WELLS FARGO & COMPANY/MN | 44 / 29 | $52.1B |
| RAYMOND JAMES FINANCIAL INC | 44 / 29 | $32.4B |
| Advisory Services Network, LLC | 44 / 29 | $739.2M |
| BANK OF AMERICA CORP /DE/ | 43 / 29 | $122.0B |
Ranked by how many of Mad River Investors's top 29 disclosed names each fund also holds: a cross-fund conviction signal from the latest 13F of every tracked manager.
Bars show each stock's share of the portfolio. Click a row for its position history.
| # | Security | Value | Shares | % Port | Last move | History |
|---|---|---|---|---|---|---|
| 1 | Texas Pacific Land Corporati COM | $124.9M | 285.3K | 46.7% | ▲+0.1% Added · +210 sh | |
| 2 | Permian Basin Rty TR UNIT BEN INT | $25.2M | 1.01M | 9.4% | ▲+0.2% Added · +2K sh | |
| 3 | Landbridge Company LLC CL A | $21.2M | 268.0K | 7.9% | ▲+0.6% Added · +2K sh | |
| 4 | Hawaiian Elec Inds Inc MTN B COM | $17.9M | 1.32M | 6.7% | ▲+0.4% Added · +5K sh | |
| 5 | Grayscale Bitcoin Trust ETF SHS REP COM UT | $16.4M | 360.1K | 6.1% | —Held | |
| 6 | Miami Intl Hldgs Inc COM | $10.7M | 289.0K | 4.0% | ▲+256% Added · +208K sh | |
| 7 | Waterbridge Infrastructure L CL A SHS REPSTG | $9.2M | 267.8K | 3.4% | ▼−1.1% Reduced · −3K sh | |
| 8 | Mesabi TR CTF BEN INT | $8.2M | 323.7K | 3.1% | ▲+0.7% Added · +2K sh | |
| 9 | Wheaton Precious Metals Corp COM | $6.3M | 56.2K | 2.4% | ▼−37% Reduced · −33K sh | |
| 10 | Franco Nev Corp COM | $4.7M | 22.5K | 1.8% | ▼−4.6% Reduced · −1K sh | |
| 11 | Fidelity Wise Origin Bitcoin SHS | $3.6M | 70.4K | 1.3% | ▲~0% Added · +30 sh | |
| 12 | Carnival Corp Ltd COMMON SHARES | $2.7M | 95.4K | 1.0% | ▲New New position | |
| 13 | Vanguard Index FDS TOTAL STK MKT | $2.5M | 6.8K | 0.9% | ▼−23% Reduced · −2K sh | |
| 14 | Grayscale Bitcoin Mini TR Et SHS NEW | $2.1M | 81.5K | 0.8% | ▲+0.4% Added · +300 sh | |
| 15 | Palo Alto Networks Inc COM | $1.9M | 5.5K | 0.7% | —Held | |
| 16 | Cboe Global MKTS Inc COM | $1.6M | 6.7K | 0.6% | ▲+0.4% Added · +25 sh | |
| 17 | Apple Inc COM | $1.5M | 5.0K | 0.5% | ▼−1.0% Reduced · −50 sh | |
| 18 | Oracle Corp COM | $1.2M | 8.1K | 0.4% | —Held | |
| 19 | Intercontinental Exchange In COM | $966K | 7.8K | 0.4% | ▲+2.6% Added · +201 sh | |
| 20 | Amazon Com Inc COM | $810K | 3.4K | 0.3% | ▼−2.9% Reduced · −100 sh | |
| 21 | Unitedhealth Group Inc COM | $707K | 1.7K | 0.3% | —Held | |
| 22 | Cisco Sys Inc COM | $705K | 6.0K | 0.3% | —Held | |
| 23 | Cincinnati Finl Corp COM | $667K | 3.6K | 0.2% | —Held | |
| 24 | Eaton Corp PLC SHS | $511K | 1.2K | 0.2% | —Held | |
| 25 | Rli Corp COM | $354K | 6.0K | 0.1% | —Held | |
| 26 | Berkshire Hathaway Inc Del CL B NEW | $313K | 625 | 0.1% | ▼−24% Reduced · −200 sh | |
| 27 | Johnson & Johnson COM | $305K | 1.2K | 0.1% | —Held | |
| 28 | Caci Intl Inc CL A | $211K | 455 | 0.1% | ▼−43% Reduced · −350 sh | |
| 29 | Fermi Inc COM | $151K | 16.5K | 0.1% | ▲New New position |
The public view is the crawlable proof. The same sourced dataset is available through REST and MCP for agents, research scripts, and back-office tools.
This fund page is the Follow view. The Build view lets your agent pull holdings, quarter changes, overlap, and source filings through API or MCP.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/funds/1384484/holdings"
Use Arkolith to show MAD RIVER INVESTORS's latest holdings, largest changes, and filing provenance.
Put / call positions from the 13F — totals include every disclosed option leg
| Type | Underlying | Notional value | Underlying shares |
|---|---|---|---|
| CALL · bullish | HAWAIIAN ELECTRIC INDSHE | $660K | 49K |
13F filers disclose option positions at the market value of the underlying the contracts reference, not the premium paid. A put is a bearish bet (it gains if the stock falls); a call is bullish. “Underlying shares” is the share count the contracts control, not a share holding. These legs are excluded from the equity book, weighting, concentration and sector figures above.
As-of date vs the date the SEC received each filing
| Quarter | As of | Filed | Positions | Value | Form |
|---|---|---|---|---|---|
| Q2 2026 | Jun 30, 2026 | Aug 3, 2026 | 30 | $268.1M | 13F-HR |
| Q1 2026 | Mar 31, 2026 | Apr 23, 2026 | 32 | $277.9M | 13F-HR |
| Q4 2025 | Dec 31, 2025 | Feb 6, 2026 | 35 | $219.6M | 13F-HR |
| Q3 2025 | Sep 30, 2025 | Oct 14, 2025 | 38 | $233.8M | 13F-HR |
| Q2 2025 | Jun 30, 2025 | Jul 8, 2025 | 24 | $223.3M | 13F-HR |
| Q1 2025 | Mar 31, 2025 | Apr 22, 2025 | 24 | $236.0M | 13F-HR |
| Q4 2024 | Dec 31, 2024 | Jan 16, 2025 | 26 | $215.2M | 13F-HR |
| Q3 2024 | Sep 30, 2024 | Oct 22, 2024 | 26 | $180.3M | 13F-HR |
Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. Price-derived performance is withheld until the price-source policy and freshness gate are green.