ALPHABET INC CAP STK CL A 02079K305 31122036 90450 SH SOLE 90450 0 0 AMPHENOL CORP CL A 032095101 1180200 14000 SH SOLE 14000 0 0 BERKSHIRE HATHAWAY INC DEL CL A 084670108 1494010 2 SH SOLE 2 0 0 BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 20640028 41450 SH SOLE 41450 0 0 CHAIN BRIDGE BANCORP INC CL A 15746L100 15489193 336137 SH SOLE 336137 0 0 HEICO CORP NEW CL A 422806208 7420725 32500 SH SOLE 32500 0 0 INTL GNRL INSURANCE HLDNGS L SHS G4809J106 2439720 100400 SH SOLE 100400 0 0 KINSALE CAP GROUP INC COM 49714P108 1291000 4000 SH SOLE 4000 0 0 MASTERCARD INCORPORATED CL A 57636Q104 10533077 19100 SH SOLE 19100 0 0 MOODYS CORP COM 615369105 2043585 4500 SH SOLE 4500 0 0 NORTHEAST BK PORTLAND ME COM 66405S100 2596860 21000 SH SOLE 21000 0 0 PROGRESSIVE CORP COM 743315103 7359505 35500 SH SOLE 35500 0 0 RLI CORP COM 749607107 1935850 35000 SH SOLE 35000 0 0 S&P GLOBAL INC COM 78409V104 4733640 12000 SH SOLE 12000 0 0 VISA INC COM CL A 92826C839 23769680 66150 SH SOLE 66150 0 0