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	467	60,625	SH		SOLE		60,625	0	0
3M COMPANY	COM	88579y101	912	6,680	SH		SOLE		6,680	0	0
AAC HOLDINGS INC	COM	000307108	42	182,000	SH		SOLE		182,000	0	0
ABBOTT LABORATORIES	COM	002824100	1,141	14,459	SH		SOLE		14,459	0	0
ABBVIE INC SHS	COM	00287y109	767	10,063	SH		SOLE		10,063	0	0
ACCENTURE PLC F CLASS A	COM	g1151c101	307	1,880	SH		SOLE		1,880	0	0
AIR PROD & CHEMICALS	COM	009158106	440	2,203	SH		SOLE		2,203	0	0
ALPHABET INC CLASS C	COM	02079K107	119,748	102,982	SH		SOLE		102,982	0	0
ALPHABET INC. CLASS A	COM	02079k305	1,538	1,324	SH		SOLE		1,324	0	0
AMAZON.COM INC	COM	023135106	127,734	65,514	SH		SOLE		65,514	0	0
AMERICAN TOWER CORP	COM	03027X100	118,443	543,940	SH		SOLE		543,940	0	0
AMGEN INC.	COM	031162100	980	4,836	SH		SOLE		4,836	0	0
ANSYS INC	COM	03662Q105	218,006	937,783	SH		SOLE		937,783	0	0
APPLE INC	COM	037833100	7,561	29,732	SH		SOLE		29,732	0	0
ATLASSIAN CORPORATION PLC	COM	G06242104	31,639	230,501	SH		SOLE		230,501	0	0
ATRION CORPORATION	COM	049904105	4,280	6,584	SH		SOLE		6,584	0	0
AUTO DATA PROCESSING	COM	053015103	1,897	13,880	SH		SOLE		13,880	0	0
BANK AMER CORP COM	COM	060505104	260	12,259	SH		SOLE		12,259	0	0
BECTON DICKINSON&CO	COM	075887109	443	1,928	SH		SOLE		1,928	0	0
BERKLEY W R CORP	COM	084423102	1,076	20,626	SH		SOLE		20,626	0	0
BERKSHIRE HATHAWAY INC DELAWA	COM	084670108	1,904	7	SH		SOLE		7	0	0
BERKSHIRE HATHAWAY INC CL B	COM	084670702	6,899	37,735	SH		SOLE		37,735	0	0
BIO-TECHNE CORP	COM	09073M104	150,295	792,611	SH		SOLE		792,611	0	0
BLACK KNIGHT INC	COM	09215C105	92,574	1,594,460	SH		SOLE		1,594,460	0	0
BLACKLINE INC	COM	09239B109	159,313	3,028,196	SH		SOLE		3,028,196	0	0
BRIGHT HORIZONS FAM SOL IN DEL	COM	109194100	5,804	56,905	SH		SOLE		56,905	0	0
BROOKS AUTOMATION INC	COM	114340102	59,257	1,942,841	SH		SOLE		1,942,841	0	0
CABLE ONE INC COM	COM	12685J105	93,376	56,798	SH		SOLE		56,798	0	0
CALAVO GROWERS INC	COM	128246105	3,770	65,355	SH		SOLE		65,355	0	0
CANADIAN NATL RAILWY F	COM	136375102	1,553	20,000	SH		SOLE		20,000	0	0
CANTEL MEDICAL CORP	COM	138098108	2,476	68,980	SH		SOLE		68,980	0	0
CAPITAL ONE FINL CORP COM	COM	14040H105	1,305	25,891	SH		SOLE		25,891	0	0
CARMAX INC	COM	143130102	80,722	1,499,570	SH		SOLE		1,499,570	0	0
CBRE GROUP INC	COM	12504L109	91,853	2,435,770	SH		SOLE		2,435,770	0	0
CHEVRON CORP	COM	166764100	344	4,747	SH		SOLE		4,747	0	0
CHUBB LTD	COM	h1467j104	453	4,056	SH		SOLE		4,056	0	0
CIGNA CORP	COM	125523100	386	2,179	SH		SOLE		2,179	0	0
CISCO SYSTEMS INC	COM	17275r102	2,437	61,992	SH		SOLE		61,992	0	0
COCA COLA COM	COM	191216100	1,721	38,884	SH		SOLE		38,884	0	0
COGENT COMMUNICATIONS	COM	19239V302	8,861	108,103	SH		SOLE		108,103	0	0
COLGATE-PALMOLIVE CO	COM	194162103	783	11,800	SH		SOLE		11,800	0	0
COMCAST CORP NEW CL A	COM	20030n101	2,414	70,201	SH		SOLE		70,201	0	0
CONSOLIDATED EDISON INC COM	COM	209115104	316	4,053	SH		SOLE		4,053	0	0
CONSTELLATION SOFTWR F	COM	21037x100	7,399	8,145	SH		SOLE		8,145	0	0
COSTAR GROUP INC	COM	22160N109	124,689	212,342	SH		SOLE		212,342	0	0
COSTCO WHOLESALE CO	COM	22160k105	207	727	SH		SOLE		727	0	0
COUPA SOFTWARE	COM	22266l106	14,052	100,566	SH		SOLE		100,566	0	0
CROWN CASTLE REIT INC	COM	22822v101	8,173	56,602	SH		SOLE		56,602	0	0
CVS HEALTH CORP	COM	126650100	242	4,073	SH		SOLE		4,073	0	0
DANAHER CORP	COM	235851102	101,972	736,740	SH		SOLE		736,740	0	0
DEXCOM INC	COM	252131107	272	1,009	SH		SOLE		1,009	0	0
DISCOVER FINANCIAL SERVICES	COM	254709108	1,823	51,098	SH		SOLE		51,098	0	0
DOLLAR GENERAL CORP	COM	256677105	27,417	181,558	SH		SOLE		181,558	0	0
DOUGLAS DYNAMICS INC	COM	25960R105	10,281	289,529	SH		SOLE		289,529	0	0
DUKE REALTY CORP REIT	COM	264411505	355	10,950	SH		SOLE		10,950	0	0
ECOLAB INC	COM	278865100	175,710	1,127,572	SH		SOLE		1,127,572	0	0
EDWARDS LIFESCIENCES	COM	28176e108	2,144	11,366	SH		SOLE		11,366	0	0
EMERSON ELECTRIC CO	COM	291011104	346	7,271	SH		SOLE		7,271	0	0
ENTERPRISE PRODS PART LP	COM	293792107	603	42,187	SH		SOLE		42,187	0	0
ENVESTNET INC	COM	29404K106	69,273	1,288,081	SH		SOLE		1,288,081	0	0
EQUITY RESIDENTIAL REIT	COM	29476l107	226	3,662	SH		SOLE		3,662	0	0
EVERTEC INC	COM	30040P103	3,878	170,625	SH		SOLE		170,625	0	0
EVO PAYMENTS INC	COM	26927e104	6,017	393,289	SH		SOLE		393,289	0	0
EXPONENT INC	COM	30214U102	4,943	68,732	SH		SOLE		68,732	0	0
EXXON MOBIL CORP	COM	30231g102	858	22,605	SH		SOLE		22,605	0	0
FACEBOOK INC CLASS	COM	30303m102	324	1,942	SH		SOLE		1,942	0	0
FASTENAL CO	COM	311900104	130,691	4,182,102	SH		SOLE		4,182,102	0	0
FISERV INC	COM	337738108	5,544	58,360	SH		SOLE		58,360	0	0
FLOOR & DECOR HOLDINGS, INC.	COM	339750101	5,245	163,462	SH		SOLE		163,462	0	0
FORTINET INC COM	COM	34959E109	1,038	10,263	SH		SOLE		10,263	0	0
GENERAL ELECTRIC CO	COM	369604103	276	34,737	SH		SOLE		34,737	0	0
GENUINE PARTS CO	COM	372460105	214	3,179	SH		SOLE		3,179	0	0
GLU MOBILE INC	COM	379890106	79	12,500	SH		SOLE		12,500	0	0
GUIDEWIRE SOFTWARE INC	COM	40171V100	8,882	111,992	SH		SOLE		111,992	0	0
HAMILTON LANE INC	COM	407497106	9,243	167,114	SH		SOLE		167,114	0	0
HEALTHPEAK PPTYS INC	COM	42250p103	1,127	47,254	SH		SOLE		47,254	0	0
HEICO CORP CL A	COM	422806208	50,494	790,198	SH		SOLE		790,198	0	0
HELIOS TECHNOLOGIES ORD SHS	COM	42328h109	3,765	99,281	SH		SOLE		99,281	0	0
HOME DEPOT INC	COM	437076102	681	3,648	SH		SOLE		3,648	0	0
HONEYWELL INTL INC	COM	438516106	355	2,655	SH		SOLE		2,655	0	0
IAA INC.	COM	449253103	6,005	200,437	SH		SOLE		200,437	0	0
IBM CORP	COM	459200101	527	4,753	SH		SOLE		4,753	0	0
IDEX CORP	COM	45167R104	2,982	21,595	SH		SOLE		21,595	0	0
IDEXX LABS INC	COM	45168d104	37,487	154,751	SH		SOLE		154,751	0	0
ILLINOIS TOOL WORKS	COM	452308109	311	2,187	SH		SOLE		2,187	0	0
ILLUMINA INC	COM	452327109	176,063	644,637	SH		SOLE		644,637	0	0
INTEL CORP	COM	458140100	14,378	265,667	SH		SOLE		265,667	0	0
INTUITIVE SURGICAL INC	COM	46120E602	150,600	304,114	SH		SOLE		304,114	0	0
J P MORGAN CHASE & CO	COM	46625h100	3,913	43,466	SH		SOLE		43,466	0	0
JOHN BEAN TECHNOLOGIES	COM	477839104	5,202	70,036	SH		SOLE		70,036	0	0
JOHNSON AND JOHNSON COM	COM	478160104	11,319	86,319	SH		SOLE		86,319	0	0
KANSAS CITY SOUTHERN COM NEW	COM	485170302	1,931	15,185	SH		SOLE		15,185	0	0
KEYON COMMUNI HOLD INC	COM	493312201	0	16,667	SH		SOLE		16,667	0	0
KEYSIGHT TECHNOLOGIES INC	COM	49338l103	1,824	21,803	SH		SOLE		21,803	0	0
KIMBERLY-CLARK CORP	COM	494368103	347	2,713	SH		SOLE		2,713	0	0
LABORATORY CORP AMER HLDGS COM	COM	50540R409	1,186	9,384	SH		SOLE		9,384	0	0
LEMAITRE VASCULAR	COM	525558201	2,802	112,441	SH		SOLE		112,441	0	0
LILLY ELI & CO	COM	532457108	931	6,711	SH		SOLE		6,711	0	0
LITTELFUSE INC	COM	537008104	2,642	19,801	SH		SOLE		19,801	0	0
LIVE NATION	COM	538034109	3,162	69,551	SH		SOLE		69,551	0	0
LOWE'S COMPANIES INC	COM	548661107	2,844	33,050	SH		SOLE		33,050	0	0
M & T BANK CORP	COM	55261f104	342	3,303	SH		SOLE		3,303	0	0
MAGELLAN MIDSTREAM PRTNRS LP C	COM	559080106	224	6,150	SH		SOLE		6,150	0	0
MARKEL CORP HLDG CO	COM	570535104	188,984	203,671	SH		SOLE		203,671	0	0
MARRIOTT INTERNATIONAL INC	COM	571903202	11,673	156,030	SH		SOLE		156,030	0	0
MASTERCARD INC-CLASS A	COM	57636Q104	119,792	495,910	SH		SOLE		495,910	0	0
MC DONALDS CORP	COM	580135101	574	3,470	SH		SOLE		3,470	0	0
MCCORMICK & CO INC COM NON VTG	COM	579780206	1,775	12,567	SH		SOLE		12,567	0	0
MERCK & CO. INC.	COM	58933y105	4,193	54,502	SH		SOLE		54,502	0	0
MESA LABS INC	COM	59064R109	9,494	41,992	SH		SOLE		41,992	0	0
MICROSOFT CORP	COM	594918104	17,399	110,323	SH		SOLE		110,323	0	0
MIDDLEBY CORP	COM	596278101	2,847	50,053	SH		SOLE		50,053	0	0
MOHAWK INDUSTRIES	COM	608190104	1,190	15,610	SH		SOLE		15,610	0	0
MONRO INC	COM	610236101	6,586	150,332	SH		SOLE		150,332	0	0
MOODYS CORP	COM	615369105	165,293	781,527	SH		SOLE		781,527	0	0
NEOGEN CORP COM	COM	640491106	831	12,400	SH		SOLE		12,400	0	0
NESTLE S A F SPONSORED ADR 1 A	COM	641069406	633	6,142	SH		SOLE		6,142	0	0
NEXTERA ENERGY INC SHS	COM	65339f101	201	834	SH		SOLE		834	0	0
NORFOLK SOUTHERN CO	COM	655844108	2,315	15,853	SH		SOLE		15,853	0	0
NOVANTA INC COM NPV	COM	67000b104	8,852	110,813	SH		SOLE		110,813	0	0
NOVARTIS AG F SPONSORED ADR 1	COM	66987v109	425	5,150	SH		SOLE		5,150	0	0
NUTRIEN LTD	COM	67077m108	945	27,855	SH		SOLE		27,855	0	0
O REILLY AUTOMOTIVE	COM	67103h107	13,473	44,752	SH		SOLE		44,752	0	0
OKTA, INC	COM	679295105	72,131	589,982	SH		SOLE		589,982	0	0
OLD DOMINION FGHT LINES INC CO	COM	679580100	18,354	139,831	SH		SOLE		139,831	0	0
ONESPAWORLD HOLDINGS LTD	COM	P73684113	2,310	568,924	SH		SOLE		568,924	0	0
ORTHOPEDIATRICS CORP	COM	68752L100	12,158	306,715	SH		SOLE		306,715	0	0
PAYCHEX INC	COM	704326107	3,025	48,080	SH		SOLE		48,080	0	0
PEPSICO INC	COM	713448108	1,477	12,298	SH		SOLE		12,298	0	0
PFIZER INC	COM	717081103	1,883	57,679	SH		SOLE		57,679	0	0
PINNACLE WEST CAP CORP	COM	723484101	228	3,008	SH		SOLE		3,008	0	0
PNC FINL SERVICES	COM	693475105	628	6,563	SH		SOLE		6,563	0	0
POOL CORPORATION	COM	73278l105	521	2,648	SH		SOLE		2,648	0	0
PRICE T ROWE GROUP INC	COM	74144T108	8,949	91,643	SH		SOLE		91,643	0	0
PROCTER & GAMBLE CO	COM	742718109	15,949	144,989	SH		SOLE		144,989	0	0
PROS HOLDINGS INC	COM	74346Y103	99,735	3,214,146	SH		SOLE		3,214,146	0	0
QUALCOMM INC	COM	747525103	21,168	312,905	SH		SOLE		312,905	0	0
QUALYS INC COM	COM	74758t303	89,694	1,031,085	SH		SOLE		1,031,085	0	0
REPLIGEN CORPORATION	COM	759916109	2,688	27,848	SH		SOLE		27,848	0	0
ROPER TECHNOLOGIES INC	COM	776696106	170,178	545,776	SH		SOLE		545,776	0	0
RPM INTERNATIONAL INC	COM	749685103	248	4,175	SH		SOLE		4,175	0	0
S & P GLOBAL INC	COM	78409V104	123,177	502,661	SH		SOLE		502,661	0	0
SBA COMMUNICATIONS CORP CL A	COM	78410G104	91,690	339,630	SH		SOLE		339,630	0	0
SEI INVESTMENTS CO	COM	784117103	438	9,451	SH		SOLE		9,451	0	0
SERVICE CORP INTL	COM	817565104	274	7,000	SH		SOLE		7,000	0	0
SITEONE LANDSCAPE SUPPLY, INC.	COM	82982L103	9,000	122,252	SH		SOLE		122,252	0	0
SMITH A O	COM	831865209	358	9,467	SH		SOLE		9,467	0	0
SOUTHERN COMPANY	COM	842587107	214	3,949	SH		SOLE		3,949	0	0
STERIS PLC	COM	G8473t100	483	3,451	SH		SOLE		3,451	0	0
TELADOC INC	COM	87918A105	10,098	65,141	SH		SOLE		65,141	0	0
TELEFLEX INC COM	COM	879369106	107,091	365,673	SH		SOLE		365,673	0	0
THE DESCARTES SYSTEMS GROUP IN	COM	249906108	5,315	154,545	SH		SOLE		154,545	0	0
THERMO FISHER SCIENTIFIC INC	COM	883556102	92,856	327,419	SH		SOLE		327,419	0	0
TRACTOR SUPPLY COMP	COM	892356106	761	9,002	SH		SOLE		9,002	0	0
TRANSDIGM GROUP INC	COM	893641100	102,690	320,716	SH		SOLE		320,716	0	0
TREX COMPANY, INC.	COM	89531P105	9,046	112,873	SH		SOLE		112,873	0	0
TRIMBLE INC	COM	896239100	1,468	46,124	SH		SOLE		46,124	0	0
TRUIST FINANCIAL ORD SHS	COM	89832Q109	395	12,818	SH		SOLE		12,818	0	0
TRUPANION, INC.	COM	898202106	5,547	213,104	SH		SOLE		213,104	0	0
TWILIO INC.	COM	90138F102	24,637	275,310	SH		SOLE		275,310	0	0
TYLER TECHNOLOGIES INC	COM	902252105	126,437	426,347	SH		SOLE		426,347	0	0
U S BANCORP	COM	902973304	856	24,849	SH		SOLE		24,849	0	0
UNION PACIFIC CORP	COM	907818108	238	1,691	SH		SOLE		1,691	0	0
UNITED PARCEL SRVC CLASS B	COM	911312106	223	2,391	SH		SOLE		2,391	0	0
UNITED TECHNOLOGIES CORP.	COM	913017109	536	5,680	SH		SOLE		5,680	0	0
UNITEDHEALTH GRP INC	COM	91324p102	2,017	8,089	SH		SOLE		8,089	0	0
VEEVA SYSTEMS, INC.	COM	922475108	54,421	348,027	SH		SOLE		348,027	0	0
VENTAS INC REIT	COM	92276f100	545	20,339	SH		SOLE		20,339	0	0
VERISK ANALYTICS INC	COM	92345Y106	171,027	1,227,058	SH		SOLE		1,227,058	0	0
VERIZON COMMUNICATN	COM	92343v104	830	15,456	SH		SOLE		15,456	0	0
VISA INC CL A	COM	92826C839	187,539	1,163,971	SH		SOLE		1,163,971	0	0
VULCAN MATERIALS CO	COM	929160109	158,070	1,462,659	SH		SOLE		1,462,659	0	0
W.P. CAREY INC. REIT	COM	92936u109	296	5,095	SH		SOLE		5,095	0	0
WABTEC	COM	929740108	1,560	32,410	SH		SOLE		32,410	0	0
WALMART INC	COM	931142103	505	4,444	SH		SOLE		4,444	0	0
WALT DISNEY CO	COM	254687106	562	5,816	SH		SOLE		5,816	0	0
WASTE CONNECTIONS INC	COM	94106B101	177,544	2,290,893	SH		SOLE		2,290,893	0	0
WATSCO INC	COM	942622200	3,623	22,929	SH		SOLE		22,929	0	0
WAYFAIR	COM	94419L101	3,516	65,792	SH		SOLE		65,792	0	0
WD-40 COMPANY	COM	929236107	3,536	17,605	SH		SOLE		17,605	0	0
WELLS FARGO BK N A	COM	949746101	1,552	54,082	SH		SOLE		54,082	0	0
ISHARES CORE S&P MID CAP ETF	ETFS	464287507	911	6,334	SH		SOLE		6,334	0	0
ISHARES CORE S&P SMALL CAP ETF	ETFS	464287804	348	6,199	SH		SOLE		6,199	0	0
ISHARES MSCI EAFE ETF	ETFS	464287465	543	10,157	SH		SOLE		10,157	0	0
SPDR GOLD TRUST	ETFS	78463v107	227	1,533	SH		SOLE		1,533	0	0
VANGUARD DIVIDEND APPREC	ETFS	921908844	1,123	10,858	SH		SOLE		10,858	0	0
VANGUARD FTSE ALL WORLD EX US	ETFS	922042775	2,665	64,974	SH		SOLE		64,974	0	0
VANGUARD FTSE EMERGING MARKETS	ETFS	922042858	598	17,836	SH		SOLE		17,836	0	0
VANGUARD HIGH DIVIDEND YIELD E	ETFS	921946406	673	9,517	SH		SOLE		9,517	0	0
VANGUARD MID CAP ETF	ETFS	922908629	333	2,533	SH		SOLE		2,533	0	0
VANGUARD REIT ETF	ETFS	922908553	1,059	15,160	SH		SOLE		15,160	0	0
VANGUARD S&P 500 ETF	ETFS	922908363	4,605	19,447	SH		SOLE		19,447	0	0
VANGUARD TOTAL STK MKT ETF	ETFS	922908769	337	2,615	SH		SOLE		2,615	0	0