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The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Expires: July 31, 2015
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
ALPHABET INC CAP STK CL A 02079K305 37,863,352 105,950 SH SOLE 105,950 0 0
AMPHENOL CORP CL A 032095101 1,234,240 7,000 SH SOLE 7,000 0 0
BERKSHIRE HATHAWAY INC DEL CL A 084670108 1,497,700 2 SH SOLE 2 0 0
BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 20,741,166 41,450 SH SOLE 41,450 0 0
CHAIN BRIDGE BANCORP INC CL A 15746L100 14,050,461 334,137 SH SOLE 334,137 0 0
HEICO CORP NEW CL A 422806208 6,834,615 26,500 SH SOLE 26,500 0 0
INTL GNRL INSURANCE HLDNGS L SHS G4809J106 2,104,068 80,400 SH SOLE 80,400 0 0
KINSALE CAP GROUP INC COM 49714P108 1,319,240 4,000 SH SOLE 4,000 0 0
MASTERCARD INCORPORATED CL A 57636Q104 9,809,760 19,100 SH SOLE 19,100 0 0
MOODYS CORP COM 615369105 2,038,140 4,500 SH SOLE 4,500 0 0
NORTHEAST BK PORTLAND ME COM 66405S100 1,590,360 12,000 SH SOLE 12,000 0 0
PROGRESSIVE CORP COM 743315103 5,570,475 25,500 SH SOLE 25,500 0 0
RLI CORP COM 749607107 2,067,450 35,000 SH SOLE 35,000 0 0
S&P GLOBAL INC COM 78409V104 4,887,120 12,000 SH SOLE 12,000 0 0
VISA INC COM CL A 92826C839 22,695,404 66,150 SH SOLE 66,150 0 0