MAD RIVER INVESTORS

BOSTON, MA · CIK 1384484 · 13F filing filed 2026-08-03

No investment adviser registration (Form ADV) found for this filer. It may be a parent company whose subsidiaries are the registered advisers, a bank or insurer, or a manager based outside the US.

Others nearbyBoston, MA

$267.4m reported value -3.5% vs Q1 2026

29positions

91.5%in top 10

2 new 10 added 8 reduced 4 sold out vs Q1 2026

Options: 1 call positions ($660.3k notional), 0 put positions (— notional) – listed below, not included above.

Holdings, Q2 2026

The small lines show how much was held over the last 4 quarters (adjusted for stock splits).

#	Security	Ticker	Shares	Value	% of portfolio	Change	Shares change
1	TEXAS PACIFIC LAND CORPORATI COM TPL	TPL	285,330	$124.9m46.69%	46.69%	Added +210	+210 0.1%
2	PERMIAN BASIN RTY TR UNIT BEN INT PBT	PBT	1,005,152	$25.2m9.41%	9.41%	Added +2.0k	+2,012 0.2%
3	LANDBRIDGE COMPANY LLC CL A LB	LB	267,953	$21.2m7.94%	7.94%	Added +1.6k	+1,568 0.6%
4	HAWAIIAN ELEC INDUSTRIES COM HE	HE	1,321,850	$17.9m6.69%	6.69%	Added +4.8k	+4,800 0.4%
5	GRAYSCALE BITCOIN TRUST ETF SHS REP COM UT GBTC	GBTC	360,139	$16.4m6.13%	6.13%	Unchanged
6	MIAMI INTL HLDGS INC COM MIAX	MIAX	289,000	$10.7m4.02%	4.02%	Added +207.8k	+207,750 255.7%
7	WATERBRIDGE INFRASTRUCTURE L CL A SHS REPSTG WBI	WBI	267,801	$9.2m3.43%	3.43%	Reduced -3.1k	-3,099 -1.1%
8	MESABI TR CTF BEN INT MSB	MSB	323,735	$8.2m3.06%	3.06%	Added +2.2k	+2,189 0.7%
9	WHEATON PRECIOUS METALS CORP COM WPM	WPM	56,173	$6.3m2.36%	2.36%	Reduced -33.1k	-33,098 -37.1%
10	FRANCO NEV CORP COM FNV	FNV	22,506	$4.7m1.75%	1.75%	Reduced -1.1k	-1,084 -4.6%
11	FIDELITY WISE ORIGIN BITCOIN SHS FBTC	FBTC	70,369	$3.6m1.34%	1.34%	Added +30	+30 0.0%
12	CARNIVAL CORP LTD COMMON SHARES CCL	CCL	95,373	$2.7m1.02%	1.02%	New
13	VANGUARD INDEX FDS TOTAL STK MKT VTI	VTI	6,800	$2.5m0.94%	0.94%	Reduced -2.0k	-2,000 -22.7%
14	GRAYSCALE BITCOIN MINI TR ET SHS NEW BTC	BTC	81,517	$2.1m0.79%	0.79%	Added +300	+300 0.4%
15	PALO ALTO NETWORKS INC COM PANW	PANW	5,484	$1.9m0.70%	0.70%	Unchanged
16	CBOE GLOBAL MKTS INC COM CBOE	CBOE	6,705	$1.6m0.61%	0.61%	Added +25	+25 0.4%
17	APPLE INC COM AAPL	AAPL	5,050	$1.5m0.55%	0.55%	Reduced -50	-50 -1.0%
18	ORACLE CORP COM ORCL	ORCL	8,050	$1.2m0.44%	0.44%	Unchanged
19	INTERCONTINENTAL EXCHANGE IN COM ICE	ICE	7,846	$965.9k0.36%	0.36%	Added +201	+201 2.6%
20	AMAZON COM INC COM AMZN	AMZN	3,400	$810.4k0.30%	0.30%	Reduced -100	-100 -2.9%
21	UNITEDHEALTH GROUP INC COM UNH	UNH	1,700	$706.6k0.26%	0.26%	Unchanged
22	CISCO SYS INC COM CSCO	CSCO	6,000	$704.8k0.26%	0.26%	Unchanged
23	CINCINNATI FINL CORP COM CINF	CINF	3,600	$666.5k0.25%	0.25%	Unchanged
24	EATON CORP PLC SHS ETN	ETN	1,200	$511.3k0.19%	0.19%	Unchanged
25	RLI CORP COM RLI	RLI	6,000	$354.4k0.13%	0.13%	Unchanged
26	BERKSHIRE HATHAWAY INC DEL CL B NEW BRK.B	BRK.B	625	$312.7k0.12%	0.12%	Reduced -200	-200 -24.2%
27	JOHNSON & JOHNSON COM JNJ	JNJ	1,200	$304.8k0.11%	0.11%	Unchanged
28	CACI INTL INC CL A CACI	CACI	455	$210.8k0.08%	0.08%	Reduced -350	-350 -43.5%
29	FERMI INC COM FRMI	FRMI	16,500	$151.1k0.06%	0.06%	New

Sold out since Q1 2026

Security	Ticker	Shares held before	Value then
CARNIVAL CORP		156,181	$4.0m156.2k shares
ROYAL GOLD INC RGLD	RGLD	2,463	$626.8k2.5k shares
JPMORGAN CHASE & CO JPM	JPM	1,417	$416.8k1.4k shares
VANGUARD SPECIALIZED FUNDS VIG	VIG	1,000	$215.1k1.0k shares

Options (notional value)

Underlying	Ticker	Type	Shares controlled	Notional	Change
HAWAIIAN ELEC INDUSTRIES HE · Call	HE	Call	48,800	$660.3k48.8k shares	Added