MAD RIVER INVESTORS

CIK

1384484

Location

BOSTON, MA

Portfolio Value

Small $268,105,956

Diversification

Moderately concentrated

Filing Date

Global Rank

#5,426 / 8,811 ▼ 804

Top Industry

Oil & Gas E&P 60.0%

Period ended 4 months ago

Filed Aug 3, 2026 · 3mo

26 quarters · since Mar 2020

Regulatory profile

From Form ADV, the SEC filer profile, 13D/13G type codes and N-CEN, never from the name.

Holder type

Unknown

Portfolio style

Measured from the filed 13F common-share book for Jun 30, 2026, never from the firm's own description.

Style

Concentrated

The top 10 positions are 91.5% of the book (60%+)

Turnover

Low turnover

7.8% over the last four quarters (under 30%)

Horizon

Long horizon

Value-weighted holding period 16.7 quarters (12+), a floor since 5.0% of the book was already held when coverage starts

Closest benchmark: every 13F filer's combined book, active share 96.3%; sector active share 73.6% against the combined 13F book's sector weights.

Over time 26 measured quarters

How the bands are measured

Style bands measure the filed 13F common-share book each closed quarter, tested in this order. Unknown: under $10,000,000 of valued equity or 5 stocks. Index-like (100+ stocks): active share of 20% or less against the closest benchmark, which is the S&P 500, S&P MidCap 400, S&P SmallCap 600, Russell 1000, Russell 2000, Nasdaq-100 or Dow Jones Industrial Average (weighted by an index-tracking fund's reported holdings or the index's constituents nearest the quarter end, over the names resolved to companies, and only when those are 90%+ of its weight) or every 13F filer's combined book, or index series holding 80%+ of the registered fund assets it advises (N-CEN) and equal to 50%+ of its book. Systematic-like: 500+ stocks, 100%+ annual turnover and a top 10 weight of 25% or less. Concentrated: a top 10 weight of 60%+ or 12 or fewer effective positions. Diversified active: none of these. Turnover is the smaller of buys and sells over average equity value, summed over four quarters: low under 30%, high 100%+. Horizon is the value-weighted number of quarters each position has been held: short under 4, long 12+.

Clone Performance

Build a hypothetical price-return history from this filer's public 13F holdings.

View clone backtest

Portfolio Concentration

29 tracked positions · as of Jun 30, 2026 · Δ vs Mar 31, 2026

Top Position

46.6%

−2.1 pts

Top 5

76.9%

−0.3 pts

Top 10

91.5%

+0.2 pts

HHI

2,457

Moderately concentrated−169

Portfolio Trend

26 quarters · across all stocks

Sector Breakdown

As of Jun 30, 2026

Sector	% Portfolio	Value	Positions
Energy	67.3%	$180,450,962	4
Unclassified	9.2%	$24,617,502	4
Basic Materials	7.2%	$19,190,996	3
Utilities	6.9%	$18,544,894	1
Financial Services	5.5%	$14,665,930	6
Technology	2.0%	$5,426,691	5
Consumer Cyclical	1.3%	$3,535,162	2
Healthcare	0.4%	$1,011,335	2
Industrials	0.2%	$511,344	1
Real Estate	0.1%	$151,140	1

Last Quarter's Activity

Export CSV

Jun 30, 2026 vs Mar 31, 2026

Added To

Positions the filer increased

10 positions

Ticker	Company	Δ Shares	Shares	Value
MIAX	Miami International Holdings, Inc.	+207,750	289,000	$10,739,240
HE	Hawaiian Electric Industries Inc	+4,800	1,321,850	$17,884,630
MSB	Mesabi Trust	+2,189	323,735	$8,190,495
PBT	Permian Basin Royalty Trust	+2,012	1,005,152	$25,169,006
LB	LandBridge Corp	+1,568	267,953	$21,232,595
BTC	Grayscale Bitcoin Mini Trust ETF	+300	81,517	$2,115,366
TPL	Texas Pacific Land Corp	+210	285,330	$124,871,821
ICE	Intercontinental Exchange, Inc.	+201	7,846	$965,921
FBTC	Fidelity Wise Origin Bitcoin Fund	+30	70,369	$3,592,337
CBOE	Cboe Global Markets, Inc.	+25	6,705	$1,627,102
No positions match the current search.

Trimmed

Positions the filer reduced

9 positions

Ticker	Company	Δ Shares	Shares	Value
CCL	Carnival Corp Ltd.	−60,808	95,373	$2,724,806
WPM	Wheaton Precious Metals Corp.	−33,098	56,173	$6,309,351
WBI	WaterBridge Infrastructure LLC	−3,099	267,801	$9,177,540
VTI	VANGUARD TOTAL STOCK MARKET INDEX FUND	−2,000	6,800	$2,516,272
FNV	FRANCO NEVADA Corp	−1,084	22,506	$4,691,150
CACI	Caci International Inc /De/	−350	455	$210,783
BRK-B	Berkshire Hathaway Inc	−200	625	$312,743
AMZN	Amazon Com Inc	−100	3,400	$810,356
AAPL	Apple Inc.	−50	5,050	$1,461,268
No positions match the current search.

New Positions

Positions the filer opened this quarter

1 positions

Ticker	Company	Shares	Value	Open
FRMI	Fermi Inc.	16,500	$151,140
No positions match the current search.

Sold Out

Positions the filer fully exited

3 positions

Ticker	Company	Shares	Value
RGLD	Royal Gold Inc	2,463	$626,808
JPM	Jpmorgan Chase & Co	1,417	$416,824
VIG	Vanguard Specialized Funds	1,000	$215,060
No positions match the current search.

Portfolio Positions

Compact Export CSV View 13F filing

29 tracked positions · $268,105,956 total · filing declares 30 positions · $268,105,784 · as of Jun 30, 2026

All sectors Basic Materials Consumer Cyclical Energy Financial Services Healthcare Industrials Real Estate Technology Utilities

Ticker	Company	Type	Shares	Δ Shares	Value (USD)	% Δ Value	Held (qtrs)	Est. cost/share	% of Portfolio
TPL	Texas Pacific Land Corp Energy	Added	285,330	+210	$124,871,821	−7.7%	22	unpriced	46.58%
PBT	Permian Basin Royalty Trust Energy	Added	1,005,152	+2,012	$25,169,006	+16.6%	18	$12.34	9.39%
LB	LandBridge Corp Energy	Added	267,953	+1,568	$21,232,595	+15.4%	8	$37.02	7.92%
HE	Hawaiian Electric Industries Inc CALL + SHARES Utilities	Added	1,370,650	+6,700	$18,544,894	−8.4%	7	$10.31	6.92%
GBTC	Grayscale Bitcoin Trust ETF	Held	360,139	0	$16,393,527	−13.7%	10	$44.10	6.11%
MIAX	Miami International Holdings, Inc. Financial Services	Added	289,000	+207,750	$10,739,240	+239.6%	4	$42.54	4.01%
WBI	WaterBridge Infrastructure LLC Energy	Reduced	267,801	-3,099	$9,177,540	+26.5%	4	unpriced	3.42%
MSB	Mesabi Trust Basic Materials	Added	323,735	+2,189	$8,190,495	−19.1%	24	$22.90	3.05%
WPM	Wheaton Precious Metals Corp. Basic Materials	Reduced	56,173	-33,098	$6,309,351	−46.1%	26+	before history	2.35%
FNV	FRANCO NEVADA Corp Basic Materials	Reduced	22,506	-1,084	$4,691,150	−19.5%	26+	before history	1.75%
FBTC	Fidelity Wise Origin Bitcoin Fund	Added	70,369	+30	$3,592,337	−13.5%	10	$47.85	1.34%
CCL	Carnival Corp Ltd. Consumer Cyclical	Reduced	95,373	-60,808	$2,724,806	−32.6%	14	$10.45	1.02%
VTI	VANGUARD TOTAL STOCK MARKET INDEX FUND	Reduced	6,800	-2,000	$2,516,272	−10.9%	13	unpriced	0.94%
BTC	Grayscale Bitcoin Mini Trust ETF	Added	81,517	+300	$2,115,366	−13.2%	8	$28.10	0.79%
PANW	Palo Alto Networks Inc Technology	Held	5,484	0	$1,870,153	+112.7%	4	$191.42	0.70%
CBOE	Cboe Global Markets, Inc. Financial Services	Added	6,705	+25	$1,627,102	−13.3%	26+	before history	0.61%
AAPL	Apple Inc. Technology	Reduced	5,050	-50	$1,461,268	+12.9%	4	$226.74	0.55%
ORCL	Oracle Corp Technology	Held	8,050	0	$1,179,727	−0.4%	4	$254.66	0.44%
ICE	Intercontinental Exchange, Inc. Financial Services	Added	7,846	+201	$965,921	−19.7%	25	$96.13	0.36%
AMZN	Amazon Com Inc Consumer Cyclical	Reduced	3,400	-100	$810,356	+11.2%	4	$226.42	0.30%
UNH	Unitedhealth Group Inc Healthcare	Held	1,700	0	$706,571	+53.6%	4	$302.44	0.26%
CSCO	Cisco Systems, Inc. Technology	Held	6,000	0	$704,760	+51.4%	4	$68.16	0.26%
CINF	Cincinnati Financial Corp Financial Services	Held	3,600	0	$666,504	+17.7%	4	$151.77	0.25%
ETN	Eaton Corp plc Industrials	Held	1,200	0	$511,344	+19.1%	4	$363.71	0.19%
RLI	Rli Corp Financial Services	Held	6,000	0	$354,420	+3.6%	26+	before history	0.13%
BRK-B	Berkshire Hathaway Inc Financial Services	Reduced	625	-200	$312,743	−20.9%	26+	before history	0.12%
JNJ	Johnson & Johnson Healthcare	Held	1,200	0	$304,764	+3.9%	4	$171.33	0.11%
CACI	Caci International Inc /De/ Technology	Reduced	455	-350	$210,783	−51.9%	26+	before history	0.08%
FRMI	Fermi Inc. Real Estate	NEW	16,500	NEW	$151,140	NEW	1	$6.32	0.06%

Covers the securities this platform tracks: U.S.-listed common stock and the put/call positions reported on it. A 13F can also report security types outside that coverage — preferred shares, bonds, warrants, untracked share classes — so the filing's own declared total can exceed the figures above. The source filing is linked at the top of this table.