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
3M CO COM COM 88579Y101 1,368 6,232 SH   SOLE   6,232 0 0
ACCENTURE PLC IRELAND SHS CLAS COM G1151C101 955 6,221 SH   SOLE   6,221 0 0
ALPHABET INC CAP STK CL A COM 02079K305 2,300 2,218 SH   SOLE   2,218 0 0
ALPHABET INC CAP STK CL C COM 02079K107 629 610 SH   SOLE   610 0 0
ALTRIA GROUP INC COM COM 02209S103 287 4,600 SH   SOLE   4,600 0 0
AMAZON COM INC COM COM 023135106 1,708 1,180 SH   SOLE   1,180 0 0
AMERICAN EXPRESS CO COM COM 025816109 1,112 11,922 SH   SOLE   11,922 0 0
AMETEK INC NEW COM COM 031100100 25,061 329,885 SH   SOLE   329,885 0 0
AMPHENOL CORP NEW CL A COM 032095101 5,137 59,638 SH   SOLE   59,638 0 0
ANGIODYNAMICS INC COM COM 03475V101 213 12,325 SH   SOLE   12,325 0 0
ANHEUSER BUSCH INBEV SA/NV SPO COM 03524A108 13,824 125,738 SH   SOLE   125,738 0 0
APPLE INC COM COM 037833100 6,742 40,186 SH   SOLE   40,186 0 0
ARCH CAP GROUP LTD ORD COM G0450A105 14,121 164,985 SH   SOLE   164,985 0 0
AUTOZONE INC COM COM 053332102 8,395 12,941 SH   SOLE   12,941 0 0
BANK AMER CORP COM COM 060505104 1,643 54,800 SH   SOLE   54,800 0 0
BANK NEW YORK MELLON CORP COM COM 064058100 421 8,173 SH   SOLE   8,173 0 0
BECTON DICKINSON & CO COM COM 075887109 310 1,431 SH   SOLE   1,431 0 0
BERKSHIRE HATHAWAY CLASS B COM 084670702 11,276 56,527 SH   SOLE   56,527 0 0
BLACKROCK INC COM COM 09247X101 1,476 2,725 SH   SOLE   2,725 0 0
BROWN FORMAN CORP CL B COM 115637209 330 6,075 SH   SOLE   6,075 0 0
CAE INC COM COM 124765108 949 51,055 SH   SOLE   51,055 0 0
CANADIAN PAC RY LTD COM COM 13645T100 16,738 94,835 SH   SOLE   94,835 0 0
CASEYS GEN STORES INC COM COM 147528103 5,893 53,685 SH   SOLE   53,685 0 0
CASS INFORMATION SYS INC COM COM 14808P109 206 3,459 SH   SOLE   3,459 0 0
CHUBB LIMITED COM COM H1467J104 530 3,872 SH   SOLE   3,872 0 0
CITIGROUP INC COM NEW COM 172967424 238 3,525 SH   SOLE   3,525 0 0
COLGATE PALMOLIVE CO COM COM 194162103 7,115 99,265 SH   SOLE   99,265 0 0
COMCAST CORP NEW CL A COM 20030N101 1,438 42,071 SH   SOLE   42,071 0 0
COPART INC COM COM 217204106 8,011 157,302 SH   SOLE   157,302 0 0
CSW INDUSTRIALS INC COM COM 126402106 351 7,800 SH   SOLE   7,800 0 0
DIAGEO P L C SPON ADR NEW COM 25243Q205 841 6,207 SH   SOLE   6,207 0 0
DIAMOND HILL INVESTMENT GROUP COM 25264R207 219 1,058 SH   SOLE   1,058 0 0
DORMAN PRODUCTS INC COM COM 258278100 11,559 174,575 SH   SOLE   174,575 0 0
DUKE ENERGY CORP NEW COM NEW COM 26441C204 214 2,763 SH   SOLE   2,763 0 0
EATON CORP PLC SHS COM G29183103 365 4,572 SH   SOLE   4,572 0 0
ENSTAR GROUP LIMITED SHS COM G3075P101 1,013 4,820 SH   SOLE   4,820 0 0
EQUITY COMWLTH COM SH BEN INT COM 294628102 3,020 98,470 SH   SOLE   98,470 0 0
EXXON MOBIL CORP COM COM 30231G102 362 4,853 SH   SOLE   4,853 0 0
FACEBOOK INC CL A COM 30303M102 481 3,012 SH   SOLE   3,012 0 0
FEDEX CORP COM COM 31428X106 418 1,740 SH   SOLE   1,740 0 0
FIDELITY NATL INFORMATION SVCS COM 31620M106 2,831 29,401 SH   SOLE   29,401 0 0
GENERAL DYNAMICS CORP COM COM 369550108 218 989 SH   SOLE   989 0 0
GOLDMAN SACHS GROUP INC COM COM 38141G104 607 2,411 SH   SOLE   2,411 0 0
GRACO INC COM COM 384109104 7,419 162,280 SH   SOLE   162,280 0 0
HEICO CORP NEW CL A COM 422806208 35,825 504,936 SH   SOLE   504,936 0 0
HEXCEL CORP NEW COM COM 428291108 20,634 319,455 SH   SOLE   319,455 0 0
HINGHAM INSTN SVGS MASS COM COM 433323102 9,921 48,159 SH   SOLE   48,159 0 0
HOME DEPOT INC COM COM 437076102 340 1,910 SH   SOLE   1,910 0 0
HOWARD HUGHES CORP COM COM 44267D107 1,621 11,650 SH   SOLE   11,650 0 0
IDEX CORP COM COM 45167R104 11,446 80,316 SH   SOLE   80,316 0 0
ILLINOIS TOOL WKS INC COM COM 452308109 805 5,142 SH   SOLE   5,142 0 0
INGREDION INC COM COM 457187102 6,645 51,545 SH   SOLE   51,545 0 0
INTEL CORP COM COM 458140100 2,327 44,678 SH   SOLE   44,678 0 0
INTERCONTINENTAL EXCHANGE INC COM 45866F104 16,279 224,470 SH   SOLE   224,470 0 0
INTERNATIONAL BUSINESS MACHS C COM 459200101 743 4,840 SH   SOLE   4,840 0 0
INTREPID POTASH INC COM COM 46121Y102 91 25,000 SH   SOLE   25,000 0 0
ISHARES GOLD TRUST ISHARES COM 464285105 544 42,700 SH   SOLE   42,700 0 0
JOHNSON & JOHNSON COM COM 478160104 2,488 19,418 SH   SOLE   19,418 0 0
JONES LANG LASALLE INC COM COM 48020Q107 795 4,550 SH   SOLE   4,550 0 0
JPMORGAN CHASE & CO COM COM 46625H100 7,074 64,326 SH   SOLE   64,326 0 0
KAR AUCTION SVCS INC COM COM 48238T109 17,292 319,040 SH   SOLE   319,040 0 0
LEGACY TEX FINL GROUP INC COM COM 52471Y106 17,880 417,573 SH   SOLE   417,573 0 0
M & T BK CORP COM COM 55261F104 10,857 58,890 SH   SOLE   58,890 0 0
MARTIN MARIETTA MATLS INC COM COM 573284106 422 2,035 SH   SOLE   2,035 0 0
MASTERCARD INCORPORATED CL A COM 57636Q104 10,686 61,005 SH   SOLE   61,005 0 0
MCDONALDS CORP COM COM 580135101 327 2,088 SH   SOLE   2,088 0 0
MEDTRONIC PLC SHS COM G5960L103 210 2,620 SH   SOLE   2,620 0 0
MICROSOFT CORP COM COM 594918104 4,973 54,482 SH   SOLE   54,482 0 0
MONDELEZ INTL INC CL A COM 609207105 355 8,500 SH   SOLE   8,500 0 0
NEWMARKET CORP COM COM 651587107 6,565 16,345 SH   SOLE   16,345 0 0
NIKE INC CL B COM 654106103 294 4,428 SH   SOLE   4,428 0 0
NORTHERN TR CORP COM COM 665859104 543 5,270 SH   SOLE   5,270 0 0
NRG YIELD INC CL A NEW COM 62942X306 454 27,600 SH   SOLE   27,600 0 0
NRG YIELD INC CL C COM 62942X405 527 31,000 SH   SOLE   31,000 0 0
O REILLY AUTOMOTIVE INC NEW CO COM 67103H107 9,858 39,850 SH   SOLE   39,850 0 0
ORACLE CORP COM COM 68389X105 230 5,033 SH   SOLE   5,033 0 0
PAYPAL HLDGS INC COM COM 70450Y103 2,111 27,826 SH   SOLE   27,826 0 0
PEPSICO INC COM COM 713448108 922 8,446 SH   SOLE   8,446 0 0
PHILIP MORRIS INTL INC COM COM 718172109 405 4,079 SH   SOLE   4,079 0 0
PRAXAIR INC COM COM 74005P104 17,060 118,225 SH   SOLE   118,225 0 0
PROCTER AND GAMBLE CO COM COM 742718109 715 9,021 SH   SOLE   9,021 0 0
RBC BEARINGS INC COM COM 75524B104 15,644 125,959 SH   SOLE   125,959 0 0
RLI CORP COM COM 749607107 20,502 323,419 SH   SOLE   323,419 0 0
ROPER TECHNOLOGIES INC COM COM 776696106 12,302 43,829 SH   SOLE   43,829 0 0
SCHEIN HENRY INC COM COM 806407102 13,967 207,805 SH   SOLE   207,805 0 0
SEMGROUP CORP CL A COM 81663A105 7,653 357,601 SH   SOLE   357,601 0 0
STARBUCKS CORP COM COM 855244109 1,288 22,241 SH   SOLE   22,241 0 0
TARGA RES CORP COM COM 87612G101 8,974 203,959 SH   SOLE   203,959 0 0
TD AMERITRADE HLDG CORP COM COM 87236Y108 966 16,306 SH   SOLE   16,306 0 0
TE CONNECTIVITY LTD REG SHS COM H84989104 2,981 29,836 SH   SOLE   29,836 0 0
TELEDYNE TECHNOLOGIES INC COM COM 879360105 14,439 77,145 SH   SOLE   77,145 0 0
TEXAS INSTRS INC COM COM 882508104 2,725 26,230 SH   SOLE   26,230 0 0
TEXAS PAC LD TR SUB CTF PROP I COM 882610108 394 780 SH   SOLE   780 0 0
TRANSDIGM GROUP INC COM COM 893641100 9,606 31,295 SH   SOLE   31,295 0 0
TWITTER INC COM COM 90184L102 377 13,002 SH   SOLE   13,002 0 0
UNILEVER PLC SPON ADR NEW COM 904767704 531 9,562 SH   SOLE   9,562 0 0
UNITED TECHNOLOGIES CORP COM COM 913017109 774 6,155 SH   SOLE   6,155 0 0
UNITEDHEALTH GROUP INC COM COM 91324P102 1,873 8,752 SH   SOLE   8,752 0 0
US BANCORP DEL COM NEW COM 902973304 280 5,547 SH   SOLE   5,547 0 0
VANGUARD SCOTTSDALE FDS SHRT T COM 92206C409 217 2,762 SH   SOLE   2,762 0 0
VERISIGN INC COM COM 92343E102 6,351 53,570 SH   SOLE   53,570 0 0
VERISK ANALYTICS INC COM COM 92345Y106 312 3,000 SH   SOLE   3,000 0 0
VERSUM MATLS INC COM COM 92532W103 4,762 126,535 SH   SOLE   126,535 0 0
VISA INC COM CL A COM 92826C839 8,904 74,435 SH   SOLE   74,435 0 0
WATERS CORP COM COM 941848103 278 1,400 SH   SOLE   1,400 0 0
WELLS FARGO CO NEW COM COM 949746101 1,597 30,477 SH   SOLE   30,477 0 0
WHITE MTNS INS GROUP LTD COM COM G9618E107 6,934 8,430 SH   SOLE   8,430 0 0
WILLIAMS COS INC DEL COM COM 969457100 2,167 87,166 SH   SOLE   87,166 0 0
WINMARK CORP COM COM 974250102 2,304 17,615 SH   SOLE   17,615 0 0
DBX ETF TR XTRACK MSCI EURP XTRACK MSCI EURP 233051853 524 19,080 SH   SOLE   19,080 0 0
ISHARES INC MSCI PAC JP ETF MSCI PAC JP ETF 464286665 443 9,545 SH   SOLE   9,545 0 0
ISHARES TR CORE S&P SCP ETF CORE S&P SCP ETF 464287804 1,727 22,428 SH   SOLE   22,428 0 0
ISHARES TR MSCI ACWI ETF MSCI ACWI ETF 464288257 215 3,000 SH   SOLE   3,000 0 0
ISHARES TR RUS 1000 VAL ETF RUS 1000 VAL ETF 464287598 329 2,741 SH   SOLE   2,741 0 0
ISHARES TR RUS MDCP VAL ETF RUS MDCP VAL ETF 464287473 9,437 109,182 SH   SOLE   109,182 0 0
ISHARES TR SELECT DIVID ETF SELECT DIVID ETF 464287168 16,549 173,980 SH   SOLE   173,980 0 0
RYDEX ETF TRUST GUG S&P500 EQ WT 78355W106 17,455 175,459 SH   SOLE   175,459 0 0
SCHWAB STRATEGIC TR INTL EQTY INTL EQTY ETF 808524805 1,851 54,900 SH   SOLE   54,900 0 0
SPDR S&P 500 ETF TR TR UNIT 78462F103 10,890 41,384 SH   SOLE   41,384 0 0
VANGUARD TAX MANAGED INTL FD FTSE DEV MKT ETF 921943858 673 15,203 SH   SOLE   15,203 0 0
VANGUARD WHITEHALL FDS INC HIGH DIV YLD 921946406 1,105 13,400 SH   SOLE   13,400 0 0
VANGUARD INDEX FDS TOTAL STK MKT 922908769 500 3,685 SH   SOLE   3,685 0 0