DF Dent & Co 13F-HR Quarterly holdings report by institutional manager

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
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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
3-D SYS CORP DEL COM NEW	COM	88554D205	298	60,625	SH		SOLE		60,625	0	0
3M COMPANY	COM	88579y101	1,417	8,846	SH		SOLE		8,846	0	0
AAC HOLDINGS INC	COM	000307108	5	182,000	SH		SOLE		182,000	0	0
ABBOTT LABORATORIES	COM	002824100	2,447	22,481	SH		SOLE		22,481	0	0
ABBVIE INC SHS	COM	00287y109	895	10,213	SH		SOLE		10,213	0	0
ACCENTURE PLC F CLASS A	COM	g1151c101	426	1,883	SH		SOLE		1,883	0	0
ADOBE SYSTEMS INC	COM	00724F101	244	498	SH		SOLE		498	0	0
AIR PROD & CHEMICALS	COM	009158106	826	2,773	SH		SOLE		2,773	0	0
ALARM.COM	COM	011642105	5,112	92,523	SH		SOLE		92,523	0	0
ALPHABET INC CLASS C	COM	02079K107	135,306	92,070	SH		SOLE		92,070	0	0
ALPHABET INC. CLASS A	COM	02079k305	1,943	1,326	SH		SOLE		1,326	0	0
AMAZON.COM INC	COM	023135106	187,186	59,448	SH		SOLE		59,448	0	0
AMERICAN TOWER CORP	COM	03027X100	148,482	614,248	SH		SOLE		614,248	0	0
AMGEN INC.	COM	031162100	985	3,876	SH		SOLE		3,876	0	0
AMPHENOL CORP NEW CL A	COM	032095101	327	3,018	SH		SOLE		3,018	0	0
ANALOG DEVICES INC	COM	032654105	286	2,448	SH		SOLE		2,448	0	0
ANSYS INC	COM	03662Q105	302,037	923,010	SH		SOLE		923,010	0	0
APPLE INC	COM	037833100	14,486	125,082	SH		SOLE		125,082	0	0
ASPEN TECHNOLOGY, INC.	COM	045327103	4,504	35,577	SH		SOLE		35,577	0	0
ATLASSIAN CORPORATION PLC	COM	G06242104	47,594	261,808	SH		SOLE		261,808	0	0
ATRION CORPORATION	COM	049904105	9,010	14,393	SH		SOLE		14,393	0	0
AUTO DATA PROCESSING	COM	053015103	1,908	13,680	SH		SOLE		13,680	0	0
BANK AMER CORP COM	COM	060505104	349	14,472	SH		SOLE		14,472	0	0
BECTON DICKINSON&CO	COM	075887109	449	1,928	SH		SOLE		1,928	0	0
BERKLEY W R CORP	COM	084423102	1,329	21,736	SH		SOLE		21,736	0	0
BERKSHIRE HATHAWAY INC DELAWA	COM	084670108	2,240	7	SH		SOLE		7	0	0
BERKSHIRE HATHAWAY INC CL B	COM	084670702	7,626	35,812	SH		SOLE		35,812	0	0
BIO-TECHNE CORP	COM	09073M104	222,818	899,437	SH		SOLE		899,437	0	0
BLACK KNIGHT INC	COM	09215C105	167,185	1,920,563	SH		SOLE		1,920,563	0	0
BLACKLINE INC	COM	09239B109	228,489	2,549,250	SH		SOLE		2,549,250	0	0
BRIGHT HORIZONS FAM SOL IN DEL	COM	109194100	57,886	380,726	SH		SOLE		380,726	0	0
BRISTOL-MYERS SQUIBB	COM	110122108	232	3,851	SH		SOLE		3,851	0	0
BROADRIDGE FINL SOLUTIONS	COM	11133T103	292	2,214	SH		SOLE		2,214	0	0
BROOKS AUTOMATION INC	COM	114340102	55,657	1,203,129	SH		SOLE		1,203,129	0	0
C M S ENERGY CORP	COM	125896100	342	5,568	SH		SOLE		5,568	0	0
CABLE ONE INC COM	COM	12685J105	199,999	106,076	SH		SOLE		106,076	0	0
CALAVO GROWERS INC	COM	128246105	4,665	70,398	SH		SOLE		70,398	0	0
CANADIAN NATL RAILWY F	COM	136375102	1,544	14,500	SH		SOLE		14,500	0	0
CANTEL MEDICAL CORP	COM	138098108	3,284	74,737	SH		SOLE		74,737	0	0
CAPITAL ONE FINL CORP COM	COM	14040H105	1,525	21,216	SH		SOLE		21,216	0	0
CARMAX INC	COM	143130102	148,099	1,611,350	SH		SOLE		1,611,350	0	0
CBRE GROUP INC	COM	12504L109	141,928	3,021,680	SH		SOLE		3,021,680	0	0
CDW CORP COM	COM	12514G108	320	2,676	SH		SOLE		2,676	0	0
CHARTER COMMUNICATIONS, INC.	COM	16119p108	209	335	SH		SOLE		335	0	0
CHEVRON CORP	COM	166764100	305	4,238	SH		SOLE		4,238	0	0
CHUBB LTD	COM	h1467j104	466	4,010	SH		SOLE		4,010	0	0
CISCO SYSTEMS INC	COM	17275r102	2,562	65,044	SH		SOLE		65,044	0	0
COCA COLA COM	COM	191216100	1,953	39,553	SH		SOLE		39,553	0	0
COGENT COMMUNICATIONS	COM	19239V302	9,428	156,997	SH		SOLE		156,997	0	0
COLGATE-PALMOLIVE CO	COM	194162103	849	11,000	SH		SOLE		11,000	0	0
COMCAST CORP NEW CL A	COM	20030n101	3,280	70,897	SH		SOLE		70,897	0	0
CONSTELLATION SOFTWR F	COM	21037x100	8,227	7,399	SH		SOLE		7,399	0	0
COSTAR GROUP INC	COM	22160N109	190,358	224,344	SH		SOLE		224,344	0	0
COSTCO WHOLESALE CO	COM	22160k105	844	2,377	SH		SOLE		2,377	0	0
COUPA SOFTWARE	COM	22266l106	21,523	78,484	SH		SOLE		78,484	0	0
CROWDSTRIKE HOLDINGS, INC.	COM	22788c105	7,010	51,050	SH		SOLE		51,050	0	0
CROWN CASTLE REIT INC	COM	22822v101	9,084	54,557	SH		SOLE		54,557	0	0
CVS HEALTH CORP	COM	126650100	293	5,016	SH		SOLE		5,016	0	0
DANAHER CORP	COM	235851102	159,748	741,874	SH		SOLE		741,874	0	0
DISCOVER FINANCIAL SERVICES	COM	254709108	1,220	21,122	SH		SOLE		21,122	0	0
DOLLAR GENERAL CORP	COM	256677105	37,865	180,637	SH		SOLE		180,637	0	0
DOUGLAS DYNAMICS INC	COM	25960R105	12,902	377,259	SH		SOLE		377,259	0	0
DUKE REALTY CORP REIT	COM	264411505	303	8,200	SH		SOLE		8,200	0	0
EAST WEST BANCORP INC	COM	27579r104	265	8,100	SH		SOLE		8,100	0	0
ECOLAB INC	COM	278865100	240,896	1,205,444	SH		SOLE		1,205,444	0	0
EDWARDS LIFESCIENCES	COM	28176e108	2,751	34,463	SH		SOLE		34,463	0	0
EMERSON ELECTRIC CO	COM	291011104	445	6,793	SH		SOLE		6,793	0	0
ENTERPRISE PRODS PART LP	COM	293792107	627	39,712	SH		SOLE		39,712	0	0
ENVESTNET INC	COM	29404K106	109,867	1,423,885	SH		SOLE		1,423,885	0	0
EVERTEC INC	COM	30040P103	6,418	184,900	SH		SOLE		184,900	0	0
EVO PAYMENTS INC	COM	26927e104	10,895	438,420	SH		SOLE		438,420	0	0
EXACT SCIENCES CORP COM	COM	30063p105	275	2,700	SH		SOLE		2,700	0	0
EXPONENT INC	COM	30214U102	7,521	104,417	SH		SOLE		104,417	0	0
EXXON MOBIL CORP	COM	30231g102	644	18,748	SH		SOLE		18,748	0	0
FACEBOOK INC CLASS	COM	30303m102	543	2,072	SH		SOLE		2,072	0	0
FASTENAL CO	COM	311900104	186,426	4,134,542	SH		SOLE		4,134,542	0	0
FISERV INC	COM	337738108	5,400	52,406	SH		SOLE		52,406	0	0
FLOOR & DECOR HOLDINGS, INC.	COM	339750101	13,261	177,282	SH		SOLE		177,282	0	0
FORTINET INC COM	COM	34959E109	1,209	10,263	SH		SOLE		10,263	0	0
GENUINE PARTS CO	COM	372460105	226	2,379	SH		SOLE		2,379	0	0
GUIDEWIRE SOFTWARE INC	COM	40171V100	12,606	120,899	SH		SOLE		120,899	0	0
HAMILTON LANE INC	COM	407497106	11,514	178,258	SH		SOLE		178,258	0	0
HEALTHEQUITY, INC.	COM	42226A107	6,605	128,582	SH		SOLE		128,582	0	0
HEALTHPEAK PPTYS INC	COM	42250p103	1,168	43,029	SH		SOLE		43,029	0	0
HEICO CORP CL A	COM	422806208	115,690	1,304,867	SH		SOLE		1,304,867	0	0
HELIOS TECHNOLOGIES ORD SHS	COM	42328h109	3,924	107,806	SH		SOLE		107,806	0	0
HOME DEPOT INC	COM	437076102	1,149	4,138	SH		SOLE		4,138	0	0
HONEYWELL INTL INC	COM	438516106	804	4,885	SH		SOLE		4,885	0	0
IAA INC.	COM	449253103	13,974	268,371	SH		SOLE		268,371	0	0
IBM CORP	COM	459200101	499	4,098	SH		SOLE		4,098	0	0
IDEX CORP	COM	45167R104	3,952	21,667	SH		SOLE		21,667	0	0
IDEXX LABS INC	COM	45168d104	100,070	254,559	SH		SOLE		254,559	0	0
ILLINOIS TOOL WORKS	COM	452308109	423	2,187	SH		SOLE		2,187	0	0
ILLUMINA INC	COM	452327109	208,268	673,831	SH		SOLE		673,831	0	0
INTEL CORP	COM	458140100	13,459	259,929	SH		SOLE		259,929	0	0
INTUITIVE SURGICAL INC	COM	46120E602	226,782	319,619	SH		SOLE		319,619	0	0
J P MORGAN CHASE & CO	COM	46625h100	4,745	49,290	SH		SOLE		49,290	0	0
JOHN BEAN TECHNOLOGIES	COM	477839104	7,117	77,447	SH		SOLE		77,447	0	0
JOHNSON AND JOHNSON COM	COM	478160104	12,817	86,087	SH		SOLE		86,087	0	0
KANSAS CITY SOUTHERN COM NEW	COM	485170302	2,537	14,030	SH		SOLE		14,030	0	0
KEYON COMMUNI HOLD INC	COM	493312201	0	16,667	SH		SOLE		16,667	0	0
KEYSIGHT TECHNOLOGIES INC	COM	49338l103	1,964	19,887	SH		SOLE		19,887	0	0
KIMBERLY-CLARK CORP	COM	494368103	415	2,813	SH		SOLE		2,813	0	0
LABORATORY CORP AMER HLDGS COM	COM	50540R409	1,761	9,354	SH		SOLE		9,354	0	0
LEMAITRE VASCULAR	COM	525558201	6,227	191,415	SH		SOLE		191,415	0	0
LILLY ELI & CO	COM	532457108	962	6,501	SH		SOLE		6,501	0	0
LITTELFUSE INC	COM	537008104	3,960	22,329	SH		SOLE		22,329	0	0
LOWE'S COMPANIES INC	COM	548661107	4,439	26,762	SH		SOLE		26,762	0	0
M & T BANK CORP	COM	55261f104	340	3,697	SH		SOLE		3,697	0	0
MAGELLAN MIDSTREAM PRTNRS LP C	COM	559080106	503	14,708	SH		SOLE		14,708	0	0
MARKEL CORP HLDG CO	COM	570535104	216,004	221,838	SH		SOLE		221,838	0	0
MARSH & MC LENNAN COMPANIES IN	COM	571748102	260	2,265	SH		SOLE		2,265	0	0
MASTERCARD INC-CLASS A	COM	57636Q104	166,856	493,407	SH		SOLE		493,407	0	0
MC DONALDS CORP	COM	580135101	762	3,470	SH		SOLE		3,470	0	0
MCCORMICK & CO INC COM NON VTG	COM	579780206	2,262	11,655	SH		SOLE		11,655	0	0
MEDTRONIC PLC F	COM	g5960l103	299	2,876	SH		SOLE		2,876	0	0
MERCK & CO. INC.	COM	58933y105	4,298	51,818	SH		SOLE		51,818	0	0
MERGENET SOLUTIONS INC COM	COM	58950m109	10	10,000	SH		SOLE		10,000	0	0
MESA LABS INC	COM	59064R109	11,620	45,613	SH		SOLE		45,613	0	0
MICROSOFT CORP	COM	594918104	23,913	113,693	SH		SOLE		113,693	0	0
MIDDLEBY CORP	COM	596278101	2,750	30,658	SH		SOLE		30,658	0	0
MONDELEZ INTL INC	COM	609207105	423	7,365	SH		SOLE		7,365	0	0
MONRO INC	COM	610236101	6,284	154,903	SH		SOLE		154,903	0	0
MOODYS CORP	COM	615369105	215,823	744,602	SH		SOLE		744,602	0	0
NASPERS SPON ADR EACH REP 0.2	COM	631512209	240	6,750	SH		SOLE		6,750	0	0
NEOGEN CORP COM	COM	640491106	923	11,800	SH		SOLE		11,800	0	0
NESTLE S A F SPONSORED ADR 1 A	COM	641069406	951	7,974	SH		SOLE		7,974	0	0
NEWMONT GOLDCORP CORP	COM	651639106	301	4,749	SH		SOLE		4,749	0	0
NEXTERA ENERGY INC SHS	COM	65339f101	526	1,895	SH		SOLE		1,895	0	0
NORFOLK SOUTHERN CO	COM	655844108	3,432	16,036	SH		SOLE		16,036	0	0
NOVANTA INC COM NPV	COM	67000b104	10,570	100,343	SH		SOLE		100,343	0	0
NOVARTIS AG F SPONSORED ADR 1	COM	66987v109	476	5,475	SH		SOLE		5,475	0	0
NUTRIEN LTD	COM	67077m108	2,055	52,380	SH		SOLE		52,380	0	0
O REILLY AUTOMOTIVE	COM	67103h107	19,956	43,282	SH		SOLE		43,282	0	0
OKTA, INC	COM	679295105	96,846	452,867	SH		SOLE		452,867	0	0
OLD DOMINION FGHT LINES INC CO	COM	679580100	32,076	177,293	SH		SOLE		177,293	0	0
ORTHOPEDIATRICS CORP	COM	68752L100	16,725	364,215	SH		SOLE		364,215	0	0
PAYCHEX INC	COM	704326107	3,481	43,638	SH		SOLE		43,638	0	0
PEPSICO INC	COM	713448108	1,698	12,250	SH		SOLE		12,250	0	0
PFIZER INC	COM	717081103	2,457	66,950	SH		SOLE		66,950	0	0
PINNACLE WEST CAP CORP	COM	723484101	224	3,000	SH		SOLE		3,000	0	0
PNC FINL SERVICES	COM	693475105	447	4,071	SH		SOLE		4,071	0	0
POOL CORPORATION	COM	73278l105	886	2,648	SH		SOLE		2,648	0	0
PRICE T ROWE GROUP INC	COM	74144T108	12,123	94,551	SH		SOLE		94,551	0	0
PROCTER & GAMBLE CO	COM	742718109	19,997	143,871	SH		SOLE		143,871	0	0
PROS HOLDINGS INC	COM	74346Y103	111,930	3,504,376	SH		SOLE		3,504,376	0	0
QUALCOMM INC	COM	747525103	38,839	330,043	SH		SOLE		330,043	0	0
QUALYS INC COM	COM	74758t303	90,376	922,111	SH		SOLE		922,111	0	0
RAYTHEON TECHNOLOGIES ORD SHS	COM	75513e101	378	6,567	SH		SOLE		6,567	0	0
REALTY INCM CRP MD PV$1.REIT	COM	756109104	288	4,740	SH		SOLE		4,740	0	0
REPLIGEN CORPORATION	COM	759916109	6,730	45,612	SH		SOLE		45,612	0	0
REPUBLIC SVCS INC	COM	760759100	268	2,870	SH		SOLE		2,870	0	0
ROPER TECHNOLOGIES INC	COM	776696106	228,187	577,528	SH		SOLE		577,528	0	0
RPM INTERNATIONAL INC	COM	749685103	346	4,175	SH		SOLE		4,175	0	0
S & P GLOBAL INC	COM	78409V104	161,884	448,929	SH		SOLE		448,929	0	0
SALESFORCE.COM INC	COM	79466L302	312	1,242	SH		SOLE		1,242	0	0
SBA COMMUNICATIONS CORP CL A	COM	78410G104	126,603	397,522	SH		SOLE		397,522	0	0
SEI INVESTMENTS CO	COM	784117103	353	6,953	SH		SOLE		6,953	0	0
SERVICE CORP INTL	COM	817565104	479	11,354	SH		SOLE		11,354	0	0
SITEONE LANDSCAPE SUPPLY, INC.	COM	82982L103	13,003	106,622	SH		SOLE		106,622	0	0
STERIS PLC	COM	G8473t100	278	1,576	SH		SOLE		1,576	0	0
TELADOC INC	COM	87918A105	10,450	47,665	SH		SOLE		47,665	0	0
TELEFLEX INC COM	COM	879369106	157,181	461,728	SH		SOLE		461,728	0	0
THE DESCARTES SYSTEMS GROUP IN	COM	249906108	7,402	129,908	SH		SOLE		129,908	0	0
THERMO FISHER SCIENTIFIC INC	COM	883556102	144,714	327,764	SH		SOLE		327,764	0	0
TRANSDIGM GROUP INC	COM	893641100	163,861	344,884	SH		SOLE		344,884	0	0
TREX COMPANY, INC.	COM	89531P105	17,182	239,970	SH		SOLE		239,970	0	0
TRIMBLE INC	COM	896239100	566	11,615	SH		SOLE		11,615	0	0
TRUPANION, INC.	COM	898202106	10,952	138,808	SH		SOLE		138,808	0	0
TWILIO INC.	COM	90138F102	65,123	263,560	SH		SOLE		263,560	0	0
TYLER TECHNOLOGIES INC	COM	902252105	111,285	319,271	SH		SOLE		319,271	0	0
U S BANCORP	COM	902973304	875	24,420	SH		SOLE		24,420	0	0
UNION PACIFIC CORP	COM	907818108	255	1,296	SH		SOLE		1,296	0	0
UNITED PARCEL SRVC CLASS B	COM	911312106	432	2,591	SH		SOLE		2,591	0	0
UNITEDHEALTH GRP INC	COM	91324p102	2,463	7,901	SH		SOLE		7,901	0	0
VEEVA SYSTEMS, INC.	COM	922475108	111,100	395,107	SH		SOLE		395,107	0	0
VENTAS INC REIT	COM	92276f100	811	19,324	SH		SOLE		19,324	0	0
VERISK ANALYTICS INC	COM	92345Y106	241,786	1,304,763	SH		SOLE		1,304,763	0	0
VERIZON COMMUNICATN	COM	92343v104	1,026	17,242	SH		SOLE		17,242	0	0
VISA INC CL A	COM	92826C839	234,380	1,172,075	SH		SOLE		1,172,075	0	0
VULCAN MATERIALS CO	COM	929160109	212,709	1,569,345	SH		SOLE		1,569,345	0	0
W.P. CAREY INC. REIT	COM	92936u109	367	5,625	SH		SOLE		5,625	0	0
WABTEC	COM	929740108	2,611	42,200	SH		SOLE		42,200	0	0
WALMART INC	COM	931142103	691	4,941	SH		SOLE		4,941	0	0
WALT DISNEY CO	COM	254687106	949	7,651	SH		SOLE		7,651	0	0
WASTE CONNECTIONS INC	COM	94106B101	290,105	2,794,841	SH		SOLE		2,794,841	0	0
WATSCO INC	COM	942622200	5,253	22,554	SH		SOLE		22,554	0	0
WAYFAIR	COM	94419L101	8,065	27,714	SH		SOLE		27,714	0	0
WD-40 COMPANY	COM	929236107	3,618	19,109	SH		SOLE		19,109	0	0
WELLS FARGO BK N A	COM	949746101	2,020	85,934	SH		SOLE		85,934	0	0
GLOBAL X SILVER MINERS ETF	ETFS	26924g102	590	42,700	SH		SOLE		42,700	0	0
ISHARES CORE S&P 500 ETF	ETFS	464287200	1,069	3,180	SH		SOLE		3,180	0	0
ISHARES CORE S&P MID CAP ETF	ETFS	464287507	855	4,616	SH		SOLE		4,616	0	0
ISHARES CORE S&P SMALL CAP ETF	ETFS	464287804	447	6,368	SH		SOLE		6,368	0	0
ISHARES MSCI EAFE ETF	ETFS	464287465	646	10,157	SH		SOLE		10,157	0	0
ISHARES MSCI GLOBAL SILVER & M	ETFS	464286327	421	27,000	SH		SOLE		27,000	0	0
SPDR FUND CONSUMER DISCRE SELE	ETFS	81369y407	215	1,466	SH		SOLE		1,466	0	0
SPDR GOLD TRUST	ETFS	78463v107	272	1,533	SH		SOLE		1,533	0	0
VANGUARD DIVIDEND APPREC	ETFS	921908844	1,417	11,017	SH		SOLE		11,017	0	0
VANGUARD FTSE ALL WORLD EX US	ETFS	922042775	3,190	63,232	SH		SOLE		63,232	0	0
VANGUARD FTSE EMERGING MARKETS	ETFS	922042858	754	17,436	SH		SOLE		17,436	0	0
VANGUARD HEALTH CARE	ETFS	92204a504	246	1,204	SH		SOLE		1,204	0	0
VANGUARD HIGH DIVIDEND YIELD E	ETFS	921946406	811	10,021	SH		SOLE		10,021	0	0
VANGUARD INDEX FDS SMALL CP ET	ETFS	922908751	360	2,341	SH		SOLE		2,341	0	0
VANGUARD INFO TECHNOLOGY INDEX	ETFS	92204a702	330	1,058	SH		SOLE		1,058	0	0
VANGUARD MID CAP ETF	ETFS	922908629	446	2,533	SH		SOLE		2,533	0	0
VANGUARD REIT ETF	ETFS	922908553	1,172	14,846	SH		SOLE		14,846	0	0
VANGUARD S&P 500 ETF	ETFS	922908363	4,880	15,861	SH		SOLE		15,861	0	0
VANGUARD TOTAL STK MKT ETF	ETFS	922908769	554	3,253	SH		SOLE		3,253	0	0
WISDOMTREE TR INDIA ERNGS FD	ETFS	97717W422	212	9,000	SH		SOLE		9,000	0	0