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	665	81,571	SH		SOLE		81,571	0	0
3M COMPANY	COM	88579y101	1,098	6,680	SH		SOLE		6,680	0	0
A. O. SMITH CORPORATION	COM	831865209	493	10,335	SH		SOLE		10,335	0	0
AAC HOLDINGS INC	COM	000307108	129	193,025	SH		SOLE		193,025	0	0
ABBOTT LABORATORIES	COM	002824100	1,189	14,213	SH		SOLE		14,213	0	0
ABBVIE INC SHS	COM	00287y109	755	9,972	SH		SOLE		9,972	0	0
ACCENTURE PLC F CLASS A	COM	g1151c101	340	1,770	SH		SOLE		1,770	0	0
AIR PRODUCTS & CHEMICALS, INC.	COM	009158106	479	2,158	SH		SOLE		2,158	0	0
ALLEGION PLC	COM	G0176J109	2,010	19,389	SH		SOLE		19,389	0	0
ALLSTATE CORPORATION	COM	020002101	2,331	21,449	SH		SOLE		21,449	0	0
ALPHABET INC CLASS C	COM	02079K107	127,507	104,600	SH		SOLE		104,600	0	0
ALPHABET INC. CLASS A	COM	02079k305	1,423	1,165	SH		SOLE		1,165	0	0
AMAZON.COM INC	COM	023135106	112,700	64,923	SH		SOLE		64,923	0	0
AMERICAN TOWER CORP	COM	03027X100	133,389	603,216	SH		SOLE		603,216	0	0
AMGEN INC COM PV $0.0001	COM	031162100	969	5,006	SH		SOLE		5,006	0	0
ANSYS INC	COM	03662Q105	217,331	981,799	SH		SOLE		981,799	0	0
APPLE INC	COM	037833100	6,568	29,326	SH		SOLE		29,326	0	0
AT&T INC	COM	00206r102	204	5,382	SH		SOLE		5,382	0	0
AUTOMATIC DATA PROC	COM	053015103	2,157	13,361	SH		SOLE		13,361	0	0
BANK AMER CORP COM	COM	060505104	363	12,461	SH		SOLE		12,461	0	0
BANK OF HAWAII CORP	COM	062540109	253	2,942	SH		SOLE		2,942	0	0
BB&T CORPORATION	COM	054937107	624	11,700	SH		SOLE		11,700	0	0
BEACON ROOFING SUPPLY INC	COM	073685109	3,058	91,203	SH		SOLE		91,203	0	0
BECTON DICKINSON&CO	COM	075887109	399	1,578	SH		SOLE		1,578	0	0
BERKLEY W R CORP	COM	084423102	1,678	23,236	SH		SOLE		23,236	0	0
BERKSHIRE HATHAWAY INC DELAWA	COM	084670108	2,806	9	SH		SOLE		9	0	0
BERKSHIRE HATHAWAY INC CL B	COM	084670702	7,954	38,237	SH		SOLE		38,237	0	0
BIO-TECHNE CORP	COM	09073M104	147,570	754,179	SH		SOLE		754,179	0	0
BLACK KNIGHT INC	COM	09215C105	91,155	1,492,871	SH		SOLE		1,492,871	0	0
BLACKLINE INC	COM	09239B109	167,635	3,506,270	SH		SOLE		3,506,270	0	0
BRIGHT HORIZONS FAM SOL IN DEL	COM	109194100	8,596	56,367	SH		SOLE		56,367	0	0
BROOKS AUTOMATION INC	COM	114340102	134,498	3,632,133	SH		SOLE		3,632,133	0	0
CABLE ONE INC COM	COM	12685J105	28,651	22,835	SH		SOLE		22,835	0	0
CALAVO GROWERS INC	COM	128246105	5,814	61,081	SH		SOLE		61,081	0	0
CANADIAN NATL RY CO COM	COM	136375102	1,797	20,000	SH		SOLE		20,000	0	0
CANTEL MEDICAL CORP	COM	138098108	5,065	67,708	SH		SOLE		67,708	0	0
CAPITAL ONE FINL CORP COM	COM	14040H105	2,465	27,090	SH		SOLE		27,090	0	0
CARMAX INC	COM	143130102	134,607	1,529,625	SH		SOLE		1,529,625	0	0
CBRE GROUP INC	COM	12504L109	114,093	2,152,301	SH		SOLE		2,152,301	0	0
CELGENE CORP	COM	151020104	276	2,775	SH		SOLE		2,775	0	0
CHEVRON CORP	COM	166764100	648	5,462	SH		SOLE		5,462	0	0
CHUBB LTD	COM	h1467j104	654	4,050	SH		SOLE		4,050	0	0
CIGNA CORP	COM	125523100	328	2,163	SH		SOLE		2,163	0	0
CISCO SYSTEMS INC COM	COM	17275r102	3,102	62,787	SH		SOLE		62,787	0	0
COCA COLA COM	COM	191216100	2,157	39,613	SH		SOLE		39,613	0	0
COGENT COMMUNICATIONS	COM	19239V302	8,708	158,031	SH		SOLE		158,031	0	0
COLGATE-PALMOLIVE CO	COM	194162103	867	11,800	SH		SOLE		11,800	0	0
COMCAST CORP NEW CL A	COM	20030n101	6,160	136,657	SH		SOLE		136,657	0	0
CONCHO RES INC COM	COM	20605P101	1,780	26,215	SH		SOLE		26,215	0	0
CONOCOPHILLIPS	COM	20825c104	514	9,020	SH		SOLE		9,020	0	0
CONSOLIDATED EDISON INC COM	COM	209115104	382	4,044	SH		SOLE		4,044	0	0
CONSTELLATION SOFTWARE INC.	COM	21037x100	8,112	8,097	SH		SOLE		8,097	0	0
CORE LAB N.V.	COM	N22717107	1,007	21,607	SH		SOLE		21,607	0	0
COSTAR GROUP INC	COM	22160N109	142,227	239,763	SH		SOLE		239,763	0	0
COUPA SOFTWARE	COM	22266l106	3,165	24,426	SH		SOLE		24,426	0	0
CROWN CASTLE REIT INC	COM	22822v101	8,016	57,666	SH		SOLE		57,666	0	0
CVS HEALTH CORP	COM	126650100	228	3,622	SH		SOLE		3,622	0	0
DANAHER CORP	COM	235851102	103,949	719,722	SH		SOLE		719,722	0	0
DELTA AIR LINES INC	COM	247361702	230	4,000	SH		SOLE		4,000	0	0
DEXCOM INC	COM	252131107	6,280	42,077	SH		SOLE		42,077	0	0
DISCOVER FINANCIAL SERVICES	COM	254709108	5,293	65,269	SH		SOLE		65,269	0	0
DISNEY (WALT) CO COM STK	COM	254687106	666	5,107	SH		SOLE		5,107	0	0
DOLLAR GENERAL	COM	256677105	7,309	45,984	SH		SOLE		45,984	0	0
DOUGLAS DYNAMICS INC	COM	25960R105	11,146	250,085	SH		SOLE		250,085	0	0
DUKE REALTY CORP REIT	COM	264411505	372	10,950	SH		SOLE		10,950	0	0
EAST WEST BANCORP INC	COM	27579r104	332	7,500	SH		SOLE		7,500	0	0
ECOLAB INC	COM	278865100	238,369	1,203,640	SH		SOLE		1,203,640	0	0
EDWARDS LIFESCIENCES	COM	28176e108	2,880	13,096	SH		SOLE		13,096	0	0
ELI LILLY & CO	COM	532457108	797	7,129	SH		SOLE		7,129	0	0
EMERSON ELECTRIC CO	COM	291011104	704	10,526	SH		SOLE		10,526	0	0
ENTERPRISE PRDTS PRTN LPL P	COM	293792107	1,226	42,911	SH		SOLE		42,911	0	0
ENVESTNET INC	COM	29404K106	69,623	1,227,927	SH		SOLE		1,227,927	0	0
EQUITY RESIDENTIAL REIT	COM	29476l107	313	3,626	SH		SOLE		3,626	0	0
EVENTBRITE INC	COM	29975e109	2,808	158,556	SH		SOLE		158,556	0	0
EVERTEC INC	COM	30040P103	3,507	112,325	SH		SOLE		112,325	0	0
EVO PAYMENTS INC	COM	26927e104	9,201	327,216	SH		SOLE		327,216	0	0
EXACT SCIENCES CORP COM	COM	30063p105	271	3,000	SH		SOLE		3,000	0	0
EXELON CORP COM	COM	30161N101	215	4,444	SH		SOLE		4,444	0	0
EXPONENT INC	COM	30214U102	4,681	66,963	SH		SOLE		66,963	0	0
EXXON MOBIL CORP COM	COM	30231g102	1,770	25,062	SH		SOLE		25,062	0	0
FACEBOOK INC CLASS	COM	30303m102	280	1,572	SH		SOLE		1,572	0	0
FASTENAL CO	COM	311900104	145,741	4,461,015	SH		SOLE		4,461,015	0	0
FISERV INC	COM	337738108	6,537	63,100	SH		SOLE		63,100	0	0
FORTINET INC COM	COM	34959E109	788	10,263	SH		SOLE		10,263	0	0
GENERAL ELECTRIC	COM	369604103	467	52,229	SH		SOLE		52,229	0	0
GENESEE AND WYOMING INC	COM	371559105	9,154	82,835	SH		SOLE		82,835	0	0
GENUINE PARTS CO	COM	372460105	317	3,179	SH		SOLE		3,179	0	0
GLAXOSMITHKLINE PLC SPONSORED	COM	37733W105	216	5,063	SH		SOLE		5,063	0	0
GLU MOBILE INC	COM	379890106	62	12,500	SH		SOLE		12,500	0	0
GUIDEWIRE SOFTWARE INC	COM	40171V100	9,734	92,368	SH		SOLE		92,368	0	0
HAMILTON LANE INC	COM	407497106	8,469	148,679	SH		SOLE		148,679	0	0
HD SUPPLY HOLDINGS INC	COM	40416M105	886	22,621	SH		SOLE		22,621	0	0
HEALTHCARE SERVICES GROUP INC	COM	421906108	27,744	1,142,190	SH		SOLE		1,142,190	0	0
HEALTHPEAK PPTYS INC	COM	42250p103	1,686	47,325	SH		SOLE		47,325	0	0
HEICO CORP CL A	COM	422806208	9,085	93,360	SH		SOLE		93,360	0	0
HELIOS TECHNOLOGIES ORD SHS	COM	42328h109	3,804	93,760	SH		SOLE		93,760	0	0
HOME DEPOT INC	COM	437076102	611	2,634	SH		SOLE		2,634	0	0
HONEYWELL INTL INC	COM	438516106	3,243	19,166	SH		SOLE		19,166	0	0
IAA INC.	COM	449253103	2,806	67,232	SH		SOLE		67,232	0	0
IBM CORP	COM	459200101	1,217	8,370	SH		SOLE		8,370	0	0
IDEXX LABORATORIES INC	COM	45168D104	27,877	102,516	SH		SOLE		102,516	0	0
ILLINOIS TOOL WORKS	COM	452308109	325	2,074	SH		SOLE		2,074	0	0
ILLUMINA INC	COM	452327109	166,118	546,045	SH		SOLE		546,045	0	0
INTEL CORP	COM	458140100	14,595	283,234	SH		SOLE		283,234	0	0
INTUITIVE SURGICAL INC	COM	46120E602	141,525	262,117	SH		SOLE		262,117	0	0
JOHN BEAN TECHNOLOGIES	COM	477839104	6,065	61,000	SH		SOLE		61,000	0	0
JOHNSON AND JOHNSON COM	COM	478160104	12,123	93,704	SH		SOLE		93,704	0	0
JPMORGAN CHASE & CO	COM	46625h100	4,991	42,404	SH		SOLE		42,404	0	0
KANSAS CITY SOUTHERN COM NEW	COM	485170302	2,150	16,165	SH		SOLE		16,165	0	0
KEYCORP	COM	493267108	241	13,500	SH		SOLE		13,500	0	0
KEYON COMMUNI HOLD INC	COM	493312201	0	16,667	SH		SOLE		16,667	0	0
KEYSIGHT TECHNOLOGIES INC	COM	49338l103	2,625	26,992	SH		SOLE		26,992	0	0
KIMBERLY CLARK	COM	494368103	385	2,713	SH		SOLE		2,713	0	0
LABORATORY CORP AMER HLDGS COM	COM	50540R409	1,577	9,384	SH		SOLE		9,384	0	0
LEMAITRE VASCULAR	COM	525558201	3,627	106,101	SH		SOLE		106,101	0	0
LINCOLN NTL CORP IND NPV	COM	534187109	640	10,603	SH		SOLE		10,603	0	0
LITTELFUSE INC	COM	537008104	3,784	21,340	SH		SOLE		21,340	0	0
LOWE'S COMPANIES INC	COM	548661107	3,982	36,217	SH		SOLE		36,217	0	0
M & T BANK CORP	COM	55261f104	522	3,302	SH		SOLE		3,302	0	0
MAGELLAN MIDSTREAM PRTNRS LP C	COM	559080106	408	6,150	SH		SOLE		6,150	0	0
MARKEL CORP HLDG CO	COM	570535104	199,543	168,832	SH		SOLE		168,832	0	0
MASTERCARD INC-CLASS A	COM	57636Q104	122,670	451,705	SH		SOLE		451,705	0	0
MCCORMICK & CO INC COM NON VTG	COM	579780206	1,962	12,555	SH		SOLE		12,555	0	0
MCDONALDS CORP COM	COM	580135101	756	3,520	SH		SOLE		3,520	0	0
MERCK AND CO INC SHS	COM	58933y105	4,592	54,552	SH		SOLE		54,552	0	0
MESA LABS INC	COM	59064R109	9,452	39,752	SH		SOLE		39,752	0	0
MGP INGREDIENTS INC	COM	55303J106	3,604	72,546	SH		SOLE		72,546	0	0
MICROSOFT CORP	COM	594918104	15,017	108,013	SH		SOLE		108,013	0	0
MIDDLEBY CORP	COM	596278101	5,789	49,520	SH		SOLE		49,520	0	0
MOHAWK INDS INC COM	COM	608190104	1,321	10,645	SH		SOLE		10,645	0	0
MONRO INC	COM	610236101	7,479	94,655	SH		SOLE		94,655	0	0
MOODYS CORP	COM	615369105	167,925	819,826	SH		SOLE		819,826	0	0
NASPERS SPON ADR EACH REP 0.2	COM	631512209	204	6,750	SH		SOLE		6,750	0	0
NEOGEN CORP COM	COM	640491106	845	12,400	SH		SOLE		12,400	0	0
NESTLE S A REP RG SH ADR	COM	641069406	667	6,142	SH		SOLE		6,142	0	0
NORFOLK SOUTHERN CO	COM	655844108	3,022	16,819	SH		SOLE		16,819	0	0
NOVANTA INC COM NPV	COM	67000b104	8,614	105,409	SH		SOLE		105,409	0	0
NOVARTIS ADR	COM	66987v109	459	5,285	SH		SOLE		5,285	0	0
NUTRIEN LTD	COM	67077m108	1,215	24,365	SH		SOLE		24,365	0	0
O REILLY AUTOMOTIVE INC	COM	67103H107	18,687	46,892	SH		SOLE		46,892	0	0
OKTA, INC	COM	679295105	55,586	564,558	SH		SOLE		564,558	0	0
ORACLE CORPORATION	COM	68389x105	284	5,165	SH		SOLE		5,165	0	0
ORTHOPEDIATRICS CORP	COM	68752L100	10,444	296,211	SH		SOLE		296,211	0	0
PAYCHEX INC	COM	704326107	3,959	47,830	SH		SOLE		47,830	0	0
PEPSICO INC	COM	713448108	1,700	12,402	SH		SOLE		12,402	0	0
PFIZER INC	COM	717081103	2,004	55,789	SH		SOLE		55,789	0	0
PHILLIPS 66	COM	718546104	222	2,170	SH		SOLE		2,170	0	0
PINNACLE WEST CAP CORP	COM	723484101	291	3,000	SH		SOLE		3,000	0	0
PNC FINCL SERVICES GROUP	COM	693475105	1,048	7,479	SH		SOLE		7,479	0	0
POOL CORPORATION	COM	73278l105	625	3,098	SH		SOLE		3,098	0	0
PRICE T ROWE GROUP INC	COM	74144T108	11,733	102,693	SH		SOLE		102,693	0	0
PROCTER & GAMBLE CO	COM	742718109	18,199	146,317	SH		SOLE		146,317	0	0
PROS HOLDINGS INC	COM	74346Y103	128,779	2,160,719	SH		SOLE		2,160,719	0	0
QUALCOMM INC	COM	747525103	25,263	331,190	SH		SOLE		331,190	0	0
QUALYS INC COM	COM	74758t303	66,431	879,070	SH		SOLE		879,070	0	0
REALTY INCM CRP MD PV$1.REIT	COM	756109104	217	2,832	SH		SOLE		2,832	0	0
ROPER TECHNOLOGIES INC	COM	776696106	193,639	543,015	SH		SOLE		543,015	0	0
RPM INTERNATIONAL INC	COM	749685103	287	4,175	SH		SOLE		4,175	0	0
S & P GLOBAL INC	COM	78409V104	132,240	539,800	SH		SOLE		539,800	0	0
SBA COMMUNICATIONS CORP CL A	COM	78410G104	82,963	344,032	SH		SOLE		344,032	0	0
SCHLUMBERGER LTD	COM	806857108	2,229	65,221	SH		SOLE		65,221	0	0
SEI INVESTMENTS CO	COM	784117103	14,287	241,107	SH		SOLE		241,107	0	0
SERVICE CORP INTL	COM	817565104	311	6,500	SH		SOLE		6,500	0	0
SITEONE LANDSCAPE SUPPLY, INC.	COM	82982L103	9,060	122,394	SH		SOLE		122,394	0	0
SOUTHERN COMPANY	COM	842587107	242	3,925	SH		SOLE		3,925	0	0
STANLEY BLACK & DECK	COM	854502101	247	1,710	SH		SOLE		1,710	0	0
STERIS PLC	COM	G8473t100	918	6,351	SH		SOLE		6,351	0	0
STRYKER CORP	COM	863667101	201	930	SH		SOLE		930	0	0
TE CONNECTIVITY LTD F	COM	h84989104	1,659	17,801	SH		SOLE		17,801	0	0
TELADOC INC	COM	87918A105	6,434	95,009	SH		SOLE		95,009	0	0
TELEFLEX INC COM	COM	879369106	91,147	268,276	SH		SOLE		268,276	0	0
THE BOEING CO	COM	097023105	318	837	SH		SOLE		837	0	0
THE DESCARTES SYSTEMS GROUP IN	COM	249906108	2,726	67,622	SH		SOLE		67,622	0	0
THERMO FISHER SCIENTIFIC INC	COM	883556102	93,293	320,297	SH		SOLE		320,297	0	0
TRACTOR SUPPLY COMP	COM	892356106	849	9,389	SH		SOLE		9,389	0	0
TRANSDIGM GROUP INC	COM	893641100	144,995	278,478	SH		SOLE		278,478	0	0
TRANSUNION	COM	89400j107	25,060	308,958	SH		SOLE		308,958	0	0
TREX COMPANY, INC.	COM	89531P105	4,974	54,699	SH		SOLE		54,699	0	0
TRIMBLE INC	COM	896239100	51,799	1,334,676	SH		SOLE		1,334,676	0	0
TRUPANION, INC.	COM	898202106	4,232	166,493	SH		SOLE		166,493	0	0
TYLER TECHNOLOGIES INC	COM	902252105	205,505	782,875	SH		SOLE		782,875	0	0
U S BANCORP	COM	902973304	1,504	27,174	SH		SOLE		27,174	0	0
UNION PACIFIC CORP	COM	907818108	272	1,680	SH		SOLE		1,680	0	0
UNITED PARCEL SERVICE INC CL B	COM	911312106	319	2,666	SH		SOLE		2,666	0	0
UNITED TECHNOLOGIES CORP.	COM	913017109	884	6,475	SH		SOLE		6,475	0	0
UNITEDHEALTH GRP INC	COM	91324p102	1,593	7,332	SH		SOLE		7,332	0	0
VAPOTHERM INC	COM	922107107	1,803	190,433	SH		SOLE		190,433	0	0
VENTAS INC REIT	COM	92276f100	1,484	20,324	SH		SOLE		20,324	0	0
VERISK ANALYTICS INC	COM	92345Y106	233,439	1,476,152	SH		SOLE		1,476,152	0	0
VERIZON COMMUNICATIONS INC	COM	92343v104	962	15,944	SH		SOLE		15,944	0	0
VISA INC CL A	COM	92826C839	212,185	1,233,563	SH		SOLE		1,233,563	0	0
VULCAN MATERIALS CO	COM	929160109	175,563	1,160,821	SH		SOLE		1,160,821	0	0
W.P. CAREY INC. REIT	COM	92936u109	456	5,095	SH		SOLE		5,095	0	0
WALMART STORES	COM	931142103	527	4,441	SH		SOLE		4,441	0	0
WASTE CONNECTIONS INC	COM	94106B101	176,796	1,921,691	SH		SOLE		1,921,691	0	0
WATSCO INC	COM	942622200	12,030	71,106	SH		SOLE		71,106	0	0
WAYFAIR	COM	94419L101	5,595	49,905	SH		SOLE		49,905	0	0
WD-40 COMPANY	COM	929236107	3,057	16,654	SH		SOLE		16,654	0	0
WESTINGHOUSE AIR BRAKE TECHNOL	COM	929740108	1,998	27,800	SH		SOLE		27,800	0	0
WSFS FINANCIAL CORP	COM	929328102	341	7,739	SH		SOLE		7,739	0	0
BLACKROCK ENHANCED EQT DIV TR	ETFS	09251A104	92	10,000	SH		SOLE		10,000	0	0
ISHARES CORE S&P 500 ETF	ETFS	464287200	877	2,938	SH		SOLE		2,938	0	0
ISHARES CORE S&P MID CAP ETF	ETFS	464287507	1,127	5,834	SH		SOLE		5,834	0	0
ISHARES CORE S&P SMALL CAP ETF	ETFS	464287804	491	6,303	SH		SOLE		6,303	0	0
ISHARES MSCI EAFE ETF	ETFS	464287465	813	12,472	SH		SOLE		12,472	0	0
ISHARES TR MSCI EMG MKT ETF	ETFS	464287234	204	4,999	SH		SOLE		4,999	0	0
SPDR GOLD TRUST	ETFS	78463v107	213	1,533	SH		SOLE		1,533	0	0
VANGUARD DIVIDEND APPREC	ETFS	921908844	1,297	10,843	SH		SOLE		10,843	0	0
VANGUARD FTSE ALL WORLD EX US	ETFS	922042775	3,310	66,328	SH		SOLE		66,328	0	0
VANGUARD FTSE EMERGING MARK ET	ETFS	922042858	920	22,843	SH		SOLE		22,843	0	0
VANGUARD HIGH DIVIDEND YIELD E	ETFS	921946406	708	7,976	SH		SOLE		7,976	0	0
VANGUARD REIT ETF	ETFS	922908553	1,216	13,040	SH		SOLE		13,040	0	0
VANGUARD S&P 500 ETF	ETFS	922908363	5,210	19,114	SH		SOLE		19,114	0	0
VANGUARD TOTAL STK MKT ETF	ETFS	922908769	395	2,615	SH		SOLE		2,615	0	0
WISDOMTREE TR INDIA ERNGS FD	ETFS	97717W422	215	9,000	SH		SOLE		9,000	0	0