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	866	95,115	SH		SOLE		95,115	0	0
3M COMPANY	COM	88579y101	1,160	6,693	SH		SOLE		6,693	0	0
A. O. SMITH CORPORATION	COM	831865209	490	10,380	SH		SOLE		10,380	0	0
AAC HOLDINGS INC	COM	000307108	138	159,985	SH		SOLE		159,985	0	0
ABBOTT LABORATORIES	COM	002824100	1,111	13,213	SH		SOLE		13,213	0	0
ABBVIE INC SHS	COM	00287y109	652	8,972	SH		SOLE		8,972	0	0
ACCENTURE PLC F CLASS A	COM	g1151c101	327	1,770	SH		SOLE		1,770	0	0
AIR PRODUCTS & CHEMICALS, INC.	COM	009158106	489	2,158	SH		SOLE		2,158	0	0
ALLEGION PLC	COM	G0176J109	2,724	24,643	SH		SOLE		24,643	0	0
ALLSTATE CORPORATION	COM	020002101	2,950	29,014	SH		SOLE		29,014	0	0
ALPHABET INC CLASS C	COM	02079K107	98,562	91,184	SH		SOLE		91,184	0	0
ALPHABET INC. CLASS A	COM	02079k305	1,373	1,268	SH		SOLE		1,268	0	0
ALTRIA GROUP INC	COM	02209s103	211	4,450	SH		SOLE		4,450	0	0
AMAZON.COM INC	COM	023135106	123,285	65,105	SH		SOLE		65,105	0	0
AMERICAN TOWER CORP.	COM	03027X100	124,740	610,126	SH		SOLE		610,126	0	0
AMGEN INC COM PV $0.0001	COM	031162100	923	5,006	SH		SOLE		5,006	0	0
ANSYS INC	COM	03662Q105	200,385	978,345	SH		SOLE		978,345	0	0
APPLE INC	COM	037833100	6,279	31,724	SH		SOLE		31,724	0	0
AUTOMATIC DATA PROC	COM	053015103	2,209	13,361	SH		SOLE		13,361	0	0
BANK AMER CORP COM	COM	060505104	241	8,322	SH		SOLE		8,322	0	0
BANK OF HAWAII CORP	COM	062540109	244	2,942	SH		SOLE		2,942	0	0
BB&T CORPORATION	COM	054937107	575	11,700	SH		SOLE		11,700	0	0
BEACON ROOFING SUPPLY INC	COM	073685109	4,856	132,255	SH		SOLE		132,255	0	0
BECTON DICKINSON&CO	COM	075887109	372	1,475	SH		SOLE		1,475	0	0
BERKLEY W R CORP	COM	084423102	3,148	47,752	SH		SOLE		47,752	0	0
BERKSHIRE HATHAWAY INC DELAWA	COM	084670108	2,865	9	SH		SOLE		9	0	0
BERKSHIRE HATHAWAY INC CL B	COM	084670702	8,739	40,997	SH		SOLE		40,997	0	0
BIO-TECHNE CORP	COM	09073M104	125,406	601,496	SH		SOLE		601,496	0	0
BLACK KNIGHT, INC.	COM	09215C105	87,940	1,462,010	SH		SOLE		1,462,010	0	0
BLACKLINE, INC	COM	09239B109	164,217	3,068,905	SH		SOLE		3,068,905	0	0
BRIGHT HORIZONS FAM SOL IN DEL	COM	109194100	8,400	55,674	SH		SOLE		55,674	0	0
BROOKS AUTOMATION, INC	COM	114340102	135,736	3,502,866	SH		SOLE		3,502,866	0	0
CALAVO GROWERS INC	COM	128246105	5,833	60,294	SH		SOLE		60,294	0	0
CANADIAN NATL RY CO COM	COM	136375102	1,850	20,000	SH		SOLE		20,000	0	0
CANTEL MEDICAL CORP	COM	138098108	3,931	48,749	SH		SOLE		48,749	0	0
CAPITAL ONE FINL CORP COM	COM	14040H105	2,468	27,200	SH		SOLE		27,200	0	0
CARMAX INC	COM	143130102	131,822	1,518,156	SH		SOLE		1,518,156	0	0
CBRE GROUP INC	COM	12504L109	85,236	1,661,526	SH		SOLE		1,661,526	0	0
CELGENE CORP	COM	151020104	266	2,875	SH		SOLE		2,875	0	0
CHEVRON CORP	COM	166764100	1,226	9,849	SH		SOLE		9,849	0	0
CHUBB LTD	COM	h1467j104	597	4,050	SH		SOLE		4,050	0	0
CIGNA CORP	COM	125523100	311	1,974	SH		SOLE		1,974	0	0
CISCO SYSTEMS INC COM	COM	17275r102	3,422	62,527	SH		SOLE		62,527	0	0
COCA COLA COM	COM	191216100	2,017	39,613	SH		SOLE		39,613	0	0
COGENT COMMUNICATIONS	COM	19239V302	9,276	156,275	SH		SOLE		156,275	0	0
COLGATE-PALMOLIVE CO	COM	194162103	846	11,800	SH		SOLE		11,800	0	0
COMCAST CORP NEW CL A	COM	20030n101	5,825	137,768	SH		SOLE		137,768	0	0
CONOCOPHILLIPS	COM	20825c104	550	9,020	SH		SOLE		9,020	0	0
CONSOLIDATED EDISON INC COM	COM	209115104	223	2,544	SH		SOLE		2,544	0	0
CONSTELLATION SOFTWARE INC.	COM	21037x100	7,638	8,097	SH		SOLE		8,097	0	0
CORE LAB N.V.	COM	N22717107	17,250	329,948	SH		SOLE		329,948	0	0
COSTAR GROUP INC	COM	22160N109	135,483	244,527	SH		SOLE		244,527	0	0
COUPA SOFTWARE	COM	22266l106	3,066	24,213	SH		SOLE		24,213	0	0
CROWN CASTLE REIT INC SHS	COM	22822v101	7,341	56,316	SH		SOLE		56,316	0	0
DANAHER CORP DEL COM	COM	235851102	98,614	689,997	SH		SOLE		689,997	0	0
DELTA AIR LINES INC	COM	247361702	227	4,000	SH		SOLE		4,000	0	0
DEXCOM INC	COM	252131107	6,225	41,541	SH		SOLE		41,541	0	0
DISCOVER FINANCIAL SERVICES	COM	254709108	4,856	62,583	SH		SOLE		62,583	0	0
DISNEY (WALT) CO COM STK	COM	254687106	713	5,107	SH		SOLE		5,107	0	0
DOLLAR GENERAL	COM	256677105	6,252	46,258	SH		SOLE		46,258	0	0
DOUGLAS DYNAMICS INC	COM	25960R105	9,928	249,505	SH		SOLE		249,505	0	0
DUKE REALTY CORP REIT	COM	264411505	346	10,950	SH		SOLE		10,950	0	0
EAST WEST BANCORP INC	COM	27579r104	351	7,500	SH		SOLE		7,500	0	0
ECOLAB INC	COM	278865100	236,023	1,195,415	SH		SOLE		1,195,415	0	0
EDWARDS LIFESCIENCES	COM	28176e108	2,419	13,096	SH		SOLE		13,096	0	0
ELI LILLY & CO	COM	532457108	801	7,229	SH		SOLE		7,229	0	0
EMERSON ELECTRIC CO	COM	291011104	712	10,676	SH		SOLE		10,676	0	0
ENPHASE ENERGY INC	COM	29355A107	292	16,000	SH		SOLE		16,000	0	0
ENTERPRISE PRDTS PRTN LPL P	COM	293792107	1,239	42,911	SH		SOLE		42,911	0	0
ENVESTNET INC	COM	29404K106	81,174	1,187,275	SH		SOLE		1,187,275	0	0
EQUITY RESIDENTIAL REIT	COM	29476l107	291	3,838	SH		SOLE		3,838	0	0
EVENTBRITE INC	COM	29975e109	2,536	156,542	SH		SOLE		156,542	0	0
EVERTEC INC	COM	30040P103	3,620	110,696	SH		SOLE		110,696	0	0
EVO PAYMENT INC	COM	26927e104	7,839	248,633	SH		SOLE		248,633	0	0
EXACT SCIENCES CORP COM	COM	30063p105	354	3,000	SH		SOLE		3,000	0	0
EXPONENT INC	COM	30214U102	3,875	66,199	SH		SOLE		66,199	0	0
EXXON MOBIL CORP COM	COM	30231g102	2,011	26,247	SH		SOLE		26,247	0	0
FACEBOOK INC CLASS	COM	30303m102	266	1,380	SH		SOLE		1,380	0	0
FASTENAL CO	COM	311900104	144,164	4,423,569	SH		SOLE		4,423,569	0	0
FISERV INC	COM	337738108	7,189	78,856	SH		SOLE		78,856	0	0
FORTINET INC COM	COM	34959E109	789	10,263	SH		SOLE		10,263	0	0
FORTIVE CORPORATION	COM	34959J108	204	2,508	SH		SOLE		2,508	0	0
GENERAL ELECTRIC	COM	369604103	548	52,229	SH		SOLE		52,229	0	0
GENESEE AND WYOMING INC	COM	371559105	68,188	681,885	SH		SOLE		681,885	0	0
GENUINE PARTS CO	COM	372460105	329	3,179	SH		SOLE		3,179	0	0
GLU MOBILE INC	COM	379890106	90	12,500	SH		SOLE		12,500	0	0
GUIDEWIRE SOFTWARE INC	COM	40171V100	7,592	74,884	SH		SOLE		74,884	0	0
HAMILTON LANE INC	COM	407497106	8,363	146,558	SH		SOLE		146,558	0	0
HCP INC	COM	40414l109	1,510	47,211	SH		SOLE		47,211	0	0
HD SUPPLY HOLDINGS INC	COM	40416M105	2,218	55,075	SH		SOLE		55,075	0	0
HEALTHCARE SERVICES GROUP INC	COM	421906108	63,579	2,096,935	SH		SOLE		2,096,935	0	0
HEICO CORP NEW CL A	COM	422806208	10,974	106,162	SH		SOLE		106,162	0	0
HELIOS TECHNOLOGIES ORD SHS	COM	42328h109	4,276	92,146	SH		SOLE		92,146	0	0
HOME DEPOT INC	COM	437076102	558	2,684	SH		SOLE		2,684	0	0
HONEYWELL INTL INC	COM	438516106	3,664	20,986	SH		SOLE		20,986	0	0
IBM CORP	COM	459200101	1,158	8,400	SH		SOLE		8,400	0	0
IDEXX LABORATORIES INC	COM	45168D104	29,441	106,930	SH		SOLE		106,930	0	0
ILLINOIS TOOL WORKS	COM	452308109	313	2,074	SH		SOLE		2,074	0	0
ILLUMINA INC	COM	452327109	168,232	456,966	SH		SOLE		456,966	0	0
INTEL CORP	COM	458140100	13,707	286,334	SH		SOLE		286,334	0	0
INTUITIVE SURGICAL INC	COM	46120E602	135,438	258,198	SH		SOLE		258,198	0	0
JOHN BEAN TECHNOLOGIES	COM	477839104	8,756	72,288	SH		SOLE		72,288	0	0
JOHNSON AND JOHNSON COM	COM	478160104	14,714	105,643	SH		SOLE		105,643	0	0
JPMORGAN CHASE & CO	COM	46625h100	4,333	38,754	SH		SOLE		38,754	0	0
KANSAS CITY SOUTHERN COM NEW	COM	485170302	2,799	22,978	SH		SOLE		22,978	0	0
KEYON COMMUNI HOLD INC	COM	493312201	0	16,667	SH		SOLE		16,667	0	0
KEYSIGHT TECHNOLOGIES INC	COM	49338l103	2,466	27,456	SH		SOLE		27,456	0	0
KIMBERLY CLARK	COM	494368103	362	2,713	SH		SOLE		2,713	0	0
LABORATORY CORP AMER HLDGS COM	COM	50540R409	1,709	9,884	SH		SOLE		9,884	0	0
LEMAITRE VASCULAR	COM	525558201	2,932	104,794	SH		SOLE		104,794	0	0
LINCOLN NTL CORP IND NPV	COM	534187109	683	10,603	SH		SOLE		10,603	0	0
LITHIA MOTORS INC CL A	COM	536797103	3,179	26,766	SH		SOLE		26,766	0	0
LITTELFUSE INC	COM	537008104	3,722	21,037	SH		SOLE		21,037	0	0
LOWE'S COMPANIES INC	COM	548661107	3,812	37,773	SH		SOLE		37,773	0	0
M & T BANK CORP	COM	55261f104	785	4,613	SH		SOLE		4,613	0	0
MAGELLAN MIDSTREAM PRTNRS LP C	COM	559080106	394	6,150	SH		SOLE		6,150	0	0
MARKEL CORP HLDG CO	COM	570535104	172,187	158,028	SH		SOLE		158,028	0	0
MASTERCARD INC-CLASS A	COM	57636Q104	120,212	454,437	SH		SOLE		454,437	0	0
MCCORMICK & CO INC COM NON VTG	COM	579780206	1,946	12,555	SH		SOLE		12,555	0	0
MCDONALDS CORP COM	COM	580135101	713	3,435	SH		SOLE		3,435	0	0
MERCK AND CO INC SHS	COM	58933y105	4,384	52,282	SH		SOLE		52,282	0	0
MESA LABS INC	COM	59064R109	6,361	26,033	SH		SOLE		26,033	0	0
MGP INGREDIENTS INC	COM	55303J106	4,741	71,499	SH		SOLE		71,499	0	0
MICROSOFT CORP	COM	594918104	14,635	109,251	SH		SOLE		109,251	0	0
MIDDLEBY CORP	COM	596278101	6,524	48,078	SH		SOLE		48,078	0	0
MOHAWK INDS INC COM	COM	608190104	1,555	10,545	SH		SOLE		10,545	0	0
MONRO INC	COM	610236101	5,665	66,412	SH		SOLE		66,412	0	0
MOODYS CORP	COM	615369105	159,100	814,603	SH		SOLE		814,603	0	0
NASPERS SPON ADR EACH REP 0.2	COM	631512209	327	6,750	SH		SOLE		6,750	0	0
NEOGEN CORP COM	COM	640491106	770	12,400	SH		SOLE		12,400	0	0
NESTLE S A REP RG SH ADR	COM	641069406	614	5,942	SH		SOLE		5,942	0	0
NORFOLK SOUTHERN CO	COM	655844108	3,659	18,358	SH		SOLE		18,358	0	0
NOVANTA INC COM NPV	COM	67000b104	7,925	84,041	SH		SOLE		84,041	0	0
NOVARTIS ADR	COM	66987v109	483	5,285	SH		SOLE		5,285	0	0
NUTRIEN LTD	COM	67077m108	1,964	36,740	SH		SOLE		36,740	0	0
O REILLY AUTOMOTIVE INC	COM	67103H107	17,700	47,925	SH		SOLE		47,925	0	0
OKTA, INC	COM	679295105	74,842	605,956	SH		SOLE		605,956	0	0
ORACLE CORPORATION	COM	68389x105	294	5,165	SH		SOLE		5,165	0	0
ORTHOPEDIATRICS CORP	COM	68752L100	10,287	263,781	SH		SOLE		263,781	0	0
PAYCHEX INC	COM	704326107	3,936	47,830	SH		SOLE		47,830	0	0
PEPSICO INC	COM	713448108	1,633	12,452	SH		SOLE		12,452	0	0
PFIZER INC	COM	717081103	2,391	55,189	SH		SOLE		55,189	0	0
PHILIP MORRIS INTL	COM	718172109	223	2,842	SH		SOLE		2,842	0	0
PHILLIPS 66	COM	718546104	203	2,170	SH		SOLE		2,170	0	0
PINNACLE WEST CAP CORP	COM	723484101	282	3,000	SH		SOLE		3,000	0	0
PNC FINCL SERVICES GROUP	COM	693475105	1,007	7,335	SH		SOLE		7,335	0	0
POOL CORPORATION	COM	73278l105	592	3,098	SH		SOLE		3,098	0	0
PRICE T ROWE GROUP INC	COM	74144T108	12,885	117,449	SH		SOLE		117,449	0	0
PROCTER & GAMBLE CO	COM	742718109	16,096	146,792	SH		SOLE		146,792	0	0
PROS HOLDINGS INC	COM	74346Y103	157,711	2,493,068	SH		SOLE		2,493,068	0	0
QUALCOMM INC	COM	747525103	25,753	338,542	SH		SOLE		338,542	0	0
QUALYS INC COM	COM	74758t303	54,611	627,134	SH		SOLE		627,134	0	0
RED HAT INC	COM	756577102	69,204	368,578	SH		SOLE		368,578	0	0
ROPER TECHNOLOGIES INC	COM	776696106	199,462	544,592	SH		SOLE		544,592	0	0
RPM INTERNATIONAL INC	COM	749685103	255	4,175	SH		SOLE		4,175	0	0
S & P GLOBAL INC	COM	78409V104	123,228	540,971	SH		SOLE		540,971	0	0
SALESFORCE.COM INC	COM	79466L302	228	1,500	SH		SOLE		1,500	0	0
SBA COMMUNICATIONS CORP CL A	COM	78410G104	74,508	331,384	SH		SOLE		331,384	0	0
SCHLUMBERGER LTD	COM	806857108	2,620	65,917	SH		SOLE		65,917	0	0
SEI INVESTMENTS CO	COM	784117103	13,216	235,573	SH		SOLE		235,573	0	0
SERVICE CORP INTL	COM	817565104	304	6,500	SH		SOLE		6,500	0	0
SITEONE LANDSCAPE SUPPLY, INC.	COM	82982L103	8,367	120,740	SH		SOLE		120,740	0	0
STANLEY BLACK & DECK	COM	854502101	291	2,010	SH		SOLE		2,010	0	0
STERIS PLC	COM	G8473t100	946	6,351	SH		SOLE		6,351	0	0
STRYKER CORP	COM	863667101	212	1,030	SH		SOLE		1,030	0	0
TE CONNECTIVITY LTD F	COM	h84989104	2,296	23,970	SH		SOLE		23,970	0	0
TELADOC INC	COM	87918A105	6,303	94,907	SH		SOLE		94,907	0	0
TELEFLEX INC COM	COM	879369106	87,526	264,308	SH		SOLE		264,308	0	0
THE BOEING CO	COM	097023105	322	884	SH		SOLE		884	0	0
THE DESCARTES SYSTEMS GROUP IN	COM	249906108	2,472	66,893	SH		SOLE		66,893	0	0
THERMO FISHER SCNTFC	COM	883556102	63,013	214,565	SH		SOLE		214,565	0	0
TRACTOR SUPPLY COMP	COM	892356106	1,372	12,609	SH		SOLE		12,609	0	0
TRANSDIGM GROUP INC	COM	893641100	132,161	273,173	SH		SOLE		273,173	0	0
TRANSUNION	COM	89400j107	21,467	292,022	SH		SOLE		292,022	0	0
TREX COMPANY, INC.	COM	89531P105	3,876	54,052	SH		SOLE		54,052	0	0
TRIMBLE INC	COM	896239100	81,378	1,803,989	SH		SOLE		1,803,989	0	0
TRUPANION, INC.	COM	898202106	4,149	114,832	SH		SOLE		114,832	0	0
TYLER TECHNOLOGIES INC	COM	902252105	165,916	768,059	SH		SOLE		768,059	0	0
U S BANCORP	COM	902973304	1,406	26,831	SH		SOLE		26,831	0	0
UNION PACIFIC CORP	COM	907818108	326	1,930	SH		SOLE		1,930	0	0
UNITED PARCEL SERVICE INC CL B	COM	911312106	280	2,716	SH		SOLE		2,716	0	0
UNITED TECHNOLOGIES CORP.	COM	913017109	1,132	8,697	SH		SOLE		8,697	0	0
UNITEDHEALTH GRP INC	COM	91324p102	1,719	7,043	SH		SOLE		7,043	0	0
VAPOTHERM INC	COM	922107107	4,950	215,200	SH		SOLE		215,200	0	0
VENTAS INC REIT	COM	92276f100	1,389	20,324	SH		SOLE		20,324	0	0
VERISK ANALYTICS INC	COM	92345Y106	214,645	1,465,552	SH		SOLE		1,465,552	0	0
VERIZON COMMUNICATIONS INC	COM	92343v104	748	13,091	SH		SOLE		13,091	0	0
VISA INC CL A	COM	92826C839	217,613	1,253,890	SH		SOLE		1,253,890	0	0
VULCAN MATERIALS CO	COM	929160109	151,115	1,100,540	SH		SOLE		1,100,540	0	0
W.P. CAREY INC. REIT	COM	92936u109	414	5,095	SH		SOLE		5,095	0	0
WALMART STORES	COM	931142103	491	4,441	SH		SOLE		4,441	0	0
WASTE CONNECTIONS INC	COM	94106B101	157,263	1,645,355	SH		SOLE		1,645,355	0	0
WATSCO INC	COM	942622200	15,090	92,277	SH		SOLE		92,277	0	0
WAYFAIR	COM	94419L101	7,240	49,588	SH		SOLE		49,588	0	0
WD-40 COMPANY	COM	929236107	2,620	16,472	SH		SOLE		16,472	0	0
WESTINGHOUSE AIR BRAKE TECHNOL	COM	929740108	1,918	26,725	SH		SOLE		26,725	0	0
WORKDAY INC	COM	98138H101	1,142	5,553	SH		SOLE		5,553	0	0
WSFS FINANCIAL CORP	COM	929328102	3,136	75,926	SH		SOLE		75,926	0	0
BLACKROCK ENHANCED EQT DIV TR	ETFS	09251A104	89	10,000	SH		SOLE		10,000	0	0
ISHARES CORE S&P 500 ETF	ETFS	464287200	1,159	3,931	SH		SOLE		3,931	0	0
ISHARES CORE S&P MID CAP ETF	ETFS	464287507	1,133	5,834	SH		SOLE		5,834	0	0
ISHARES CORE S&P SMALL CAP ETF	ETFS	464287804	493	6,303	SH		SOLE		6,303	0	0
ISHARES MSCI EAFE ETF	ETFS	464287465	889	13,523	SH		SOLE		13,523	0	0
ISHARES RUSSELL 2000 GROWTH IN	ETFS	464287648	201	1,000	SH		SOLE		1,000	0	0
ISHARES TR MSCI EMG MKT ETF	ETFS	464287234	215	4,999	SH		SOLE		4,999	0	0
SPDR GOLD TRUST	ETFS	78463v107	204	1,533	SH		SOLE		1,533	0	0
VANGUARD DIVIDEND APPREC	ETFS	921908844	1,288	11,184	SH		SOLE		11,184	0	0
VANGUARD FTSE ALL WORLD EX US	ETFS	922042775	3,390	66,478	SH		SOLE		66,478	0	0
VANGUARD FTSE EMERGING MARK ET	ETFS	922042858	972	22,843	SH		SOLE		22,843	0	0
VANGUARD HIGH DIVIDEND YIELD E	ETFS	921946406	686	7,851	SH		SOLE		7,851	0	0
VANGUARD REIT ETF	ETFS	922908553	1,106	12,655	SH		SOLE		12,655	0	0
VANGUARD S&P 500 ETF	ETFS	922908363	5,145	19,114	SH		SOLE		19,114	0	0
VANGUARD TOTAL STK MKT ETF	ETFS	922908769	392	2,615	SH		SOLE		2,615	0	0
WISDOMTREE TR INDIA ERNGS FD	ETFS	97717W422	235	9,000	SH		SOLE		9,000	0	0