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 18,669 18,000 SH   DFND 1 0 18,000 0
ALPHABET INC CAP STK CL A 02079K305 1,037 1,000 SH   DFND 1 0 1,000 0
ALPHABET INC CAP STK CL A 02079K305 2,904 2,800 SH   DFND 1 0 2,800 0
ALPHABET INC CAP STK CL A 02079K305 67,186 64,780 SH   DFND 1 0 64,780 0
ALPHABET INC CAP STK CL C 02079K107 35,880 34,775 SH   DFND 1 0 34,775 0
BERKSHIRE HATHAWAY INC DEL CL A 084670108 11,964 40 SH   DFND 1 0 40 0
BERKSHIRE HATHAWAY INC DEL CL A 084670108 89,730 300 SH   DFND 1 0 300 0
BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 6,339 31,780 SH   DFND 1 0 31,780 0
CREDIT ACCEP CORP MICH COM 225310101 36,345 110,000 SH   DFND 1 0 110,000 0
EAGLE BULK SHIPPING INC SHS NEW Y2187A143 619 125,000 SH   DFND 1 0 125,000 0
FASTENAL CO COM 311900104 49,131 900,000 SH   DFND 1 0 900,000 0
FACEBOOK INC CL A 30303M102 18,695 117,000 SH   DFND 1 0 117,000 0
MARKEL CORP COM 570535104 2,721 2,325 SH   DFND 1 0 2,325 0
MICROSOFT CORP COM 594918104 2,190 24,000 SH   DFND 1 0 24,000 0
MICROSOFT CORP COM 594918104 913 10,000 SH   DFND 1 0 10,000 0
MICROSOFT CORP COM 594918104 139,643 1,530,000 SH   DFND 1 0 1,530,000 0
NATIONAL OILWELL VARCO INC COM 637071101 1,104 30,000 SH   DFND 1 0 30,000 0
NOW INC COM 67011P100 1,022 100,000 SH   DFND 1 0 100,000 0
NOW INC COM 67011P100 2,300 225,000 SH   DFND 1 0 225,000 0
NOW INC COM 67011P100 1,737 170,000 SH   DFND 1 0 170,000 0
SHAKE SHACK INC CL A 819047101 12,226 293,678 SH   DFND 1 0 293,678 0
TRIPADVISOR INC COM 896945201 2,453 60,000 SH   DFND 1 0 60,000 0
TRIPADVISOR INC COM 896945201 2,208 54,000 SH   DFND 1 0 54,000 0
TRUPANION INC COM 898202106 17,934 600,000 SH   DFND 1 0 600,000 0
TUCOWS INC COM NEW 898697206 3,528 63,000 SH   DFND 1 0 63,000 0
TUCOWS INC COM NEW 898697206 4,480 80,000 SH   DFND 1 0 80,000 0
TUCOWS INC COM NEW 898697206 49,616 885,992 SH   DFND 1 0 885,992 0
WABTEC CORP COM 929740108 37,037 455,000 SH   DFND 1 0 455,000 0