SEC Form 4 · Updated Daily

CSGP

— COSTAR GROUP, INC. Ownership

Insider and institutional ownership derived from SEC Form 4 filings. Click any owner to see their holdings across every company they’ve filed on, and how their position has changed over time.

Financials Ownership

Current Reporting Owners

Owner	Role	Shares Owned	As Of	Last Activity
FLORANCE ANDREW C	Director · Officer	1,806,165.03	2026-08-04	P
SIMURO FRANK	Officer	414,491	2026-03-15	F
SAINT FREDERICK G.	Officer	278,415	2026-08-01	F
Ruggles Lisa	Officer	174,915	2026-03-15	F
LOWN CHRISTIAN M.	Officer	129,653	2026-07-01	F
Boxer Gene	Officer	95,517	2026-03-15	F
DESMARAIS MICHAEL J	Officer	87,725	2026-03-15	F
Sams Louise S	Director	28,671	2026-06-23	A
Musslewhite Robert W	Director	26,539	2026-06-23	A
Hill John W	Director	22,993	2026-08-05	S
Cann Cynthia Cammett	Officer	18,822	2026-08-07	S
Brunner Angelique G.	Director	18,428	2026-06-23	A
Glaser Rachel C	Director	12,419	2026-06-23	A
McCarthy Christine M	Director	11,585	2026-06-23	A
BERISFORD JOHN L	Director	11,235	2026-06-23	A

Recent Filings

Date	Owner	Activity	Shares	Price	Owned After
2026-08-07	Cann Cynthia Cammett	Open-market sale	4,788	$30.78	18,822
2026-08-05	Hill John W	Open-market sale	3,500	$30.21	22,993
2026-08-04	FLORANCE ANDREW C	Open-market buy	83,300	$29.89	1,806,165.03
2026-08-01	SAINT FREDERICK G.	Tax withholding	1,436	$28.76	278,415
2026-08-01	Cann Cynthia Cammett	Tax withholding	1,077	$28.76	23,610
2026-07-31	Cann Cynthia Cammett	Grant / award (derivative)	26,078	$0.00	26,078
2026-07-31	Rossmann Robin Jack	Grant / award (derivative)	34,771	$0.00	34,771
2026-07-01	LOWN CHRISTIAN M.	Tax withholding	5,597	$29.36	129,653
2026-06-23	McCarthy Christine M	Grant / award	8,262	$0.00	11,585
2026-06-23	Sams Louise S	Grant / award	8,262	$0.00	28,671
2026-06-23	Musslewhite Robert W	Grant / award	8,262	$0.00	26,539
2026-06-23	Brunner Angelique G.	Grant / award	8,262	$0.00	18,428
2026-06-23	Hill John W	Grant / award	8,262	$0.00	26,493
2026-06-23	BERISFORD JOHN L	Grant / award	8,262	$0.00	11,235
2026-06-23	Glaser Rachel C	Grant / award	8,262	$0.00	12,419
2026-06-15	Cann Cynthia Cammett	Tax withholding	461	$32.04	24,687
2026-05-01	FLORANCE ANDREW C	Open-market buy	3,100	$35.82	1,722,865.03
2026-05-01	FLORANCE ANDREW C	Open-market buy	68,330	$35.17	1,719,765.03
2026-03-15	Cann Cynthia Cammett	Tax withholding	1,194	$43.63	25,148
2026-03-15	DESMARAIS MICHAEL J	Tax withholding	2,873	$43.63	87,725
2026-03-15	SIMURO FRANK	Tax withholding	11,107	$43.63	414,491
2026-03-15	Boxer Gene	Tax withholding	428	$43.63	95,517
2026-03-15	Ruggles Lisa	Tax withholding	2,977	$43.63	174,915
2026-03-15	Boxer Gene	Tax withholding	482	$43.63	95,463
2026-03-10	DESMARAIS MICHAEL J	Grant / award	17,676	—	90,598
2026-03-10	Boxer Gene	Grant / award	21,920	—	95,945
2026-03-10	LOWN CHRISTIAN M.	Grant / award	12,268	—	135,250
2026-03-10	FLORANCE ANDREW C	Grant / award	124,162	—	1,651,435.03
2026-03-10	Cann Cynthia Cammett	Grant / award	4,374	—	26,342
2026-03-06	Sams Louise S	Open-market buy	1,000	$48.36	20,409
2026-03-02	SAINT FREDERICK G.	Open-market buy	20,000	$45.33	279,851
2026-03-02	Glaser Rachel C	Open-market buy	1,000	$44.94	4,157
2026-03-01	SAINT FREDERICK G.	Tax withholding	11,096	$44.63	259,851
2026-03-01	SIMURO FRANK	Tax withholding	18,702	$44.63	425,598
2026-03-01	Ruggles Lisa	Tax withholding	8,931	$44.63	177,892
2026-03-01	Cann Cynthia Cammett	Tax withholding	1,385	$44.63	21,968
2026-03-01	DESMARAIS MICHAEL J	Tax withholding	6,353	$44.63	72,922
2026-03-01	Boxer Gene	Tax withholding	4,547	$44.63	74,025
2026-03-01	FLORANCE ANDREW C	Tax withholding	59,593	$44.63	1,527,273.03
2026-03-01	LOWN CHRISTIAN M.	Tax withholding	7,175	$44.63	122,982

Source: SEC EDGAR Form 4 filings. For informational purposes only — not investment advice.