The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
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
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 1,985 1,400 SH   DFND 1 0 1,400 0
ALPHABET INC CAP STK CL C 02079K107 990 700 SH   DFND 1 0 700 0
ALPHABET INC CAP STK CL A 02079K305 1,702 1,200 SH   DFND 1 0 1,200 0
ALPHABET INC CAP STK CL A 02079K305 175,565 123,807 SH   DFND 1 0 123,807 0
ALPHABET INC CAP STK CL C 02079K107 121,252 85,775 SH   DFND 1 0 85,775 0
AMAZON COM INC COM 023135106 828 300 SH   DFND 1 0 300 0
AMAZON COM INC COM 023135106 828 300 SH   DFND 1 0 300 0
BERKSHIRE HATHAWAY INC DEL CL A 084670108 80,190 300 SH   DFND 1 0 300 0
BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 5,673 31,780 SH   DFND 1 0 31,780 0
CARVANA CO CL A 146869102 3,293 27,400 SH   DFND 1 0 27,400 0
CREDIT ACCEP CORP MICH COM 225310101 67,660 161,477 SH   DFND 1 0 161,477 0
FACEBOOK INC CL A 30303M102 49,955 220,000 SH   DFND 1 0 220,000 0
INTERACTIVE BROKERS GROUP IN COM CL A 45841N107 922 22,074 SH   DFND 1 0 22,074 0
INTERACTIVE BROKERS GROUP IN COM CL A 45841N107 1,671 40,000 SH   DFND 1 0 40,000 0
MARKEL CORP COM 570535104 2,146 2,325 SH   DFND 1 0 2,325 0
MERCADOLIBRE INC COM 58733R102 1,084 1,100 SH   DFND 1 0 1,100 0
MICROSOFT CORP COM 594918104 157,415 773,500 SH   DFND 1 0 773,500 0
MICROSOFT CORP COM 594918104 1,628 8,000 SH   DFND 1 0 8,000 0
TRUPANION INC COM 898202106 34,152 800,000 SH   DFND 1 0 800,000 0
TUCOWS INC COM NEW 898697206 4,815 84,000 SH   DFND 1 0 84,000 0
TUCOWS INC COM NEW 898697206 4,586 80,000 SH   DFND 1 0 80,000 0
TUCOWS INC COM NEW 898697206 1,720 30,000 SH   DFND 1 0 30,000 0
TUCOWS INC COM NEW 898697206 888 15,500 SH   DFND 1 0 15,500 0
TUCOWS INC COM NEW 898697206 79,883 1,393,627 SH   DFND 1 0 1,393,627 0
UNIVAR SOLUTIONS INC COM 91336L107 843 50,000 SH   DFND 1 0 50,000 0
VISA INC COM CL A 92826C839 580 3,000 SH   DFND 1 0 3,000 0
WABTEC CORP COM 929740108 1,065 18,500 SH   DFND 1 0 18,500 0
WABTEC CORP COM 929740108 26,194 455,000 SH   DFND 1 0 455,000 0
WIX COM LTD SHS M98068105 62,774 245,000 SH   DFND 1 0 245,000 0