SEC INSIDER TRANSACTIONS

COSTAR GROUP, INC. (CSGP) Insider Transactions

Explore official ownership filings, with every record linked to its source.

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CSGP · COSTAR GROUP, INC.

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Roles: director,officer,ten_percent_owner,otherOwner nameOfficer titleOwnership: D, I, unknownoriginal or amendedTransaction fromTransaction throughFiled fromFiled throughMinimum quantityMaximum quantityMinimum priceMaximum priceMinimum calculated valueMaximum calculated valueResults per page (1–100)

OR within codes/roles; AND between categories. Roles apply to buyers and sellers. Owner predicates match the same owner. Missing values fail numeric/date filters. Value is quantity × reported price for non-derivative rows only; derivative values are unknown. Amendments stay separate; joint owners do not duplicate rows.

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Stale snapshot · Covered: filings 2026-05-14 to 2026-10-27 · 17 filings · fetched 2026-10-27T16:38:28Z

Recent reported activity

1purchase rows on this page

2sale rows on this page

17matching filing rows

Purchases and sales count original non-derivative P and S rows. Awards, gifts, exercises, derivatives and amendments are shown separately and are not described as market purchases.

Transaction / filed	Reporting owner(s)	Code / security	Quantity	Price as filed	Ownership	Source
2026-10-15Filed 2026-10-16	Rossmann Robin JackOfficer · Chief Financial Officer Filing context Reported filing row; may be amended. Do not sum filings blindly. References:	F WithholdingCommon Stock, par value $0.01 per share · Non-derivative	756D	32	Direct	Form 4 ↗0001628280-26-066186
2026-08-07Filed 2026-08-10	Cann Cynthia CammettOfficer · Chief Accounting Officer Filing context Reported filing row; may be amended. Do not sum filings blindly. References:	S Sale (market/private)Common Stock, par value $0.01 per share · Non-derivative	4,788D	30.78	Direct	Form 4 ↗0001472762-26-000012
2026-08-05Filed 2026-08-10	Hill John WDirector Filing context Reported filing row; may be amended. Do not sum filings blindly. References:	S Sale (market/private)Common Stock, par value $0.01 per share · Non-derivative	3,500D	30.21	Direct	Form 4 ↗0001351689-26-000005
2026-08-04Filed 2026-08-05	FLORANCE ANDREW CDirector · Officer · Founder and CEO Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 Average based on sales prices ranging from $29.57 to $29.99. References: F1	P Purchase (market/private)Common Stock, par value $0.01 per share · Non-derivative	83,300A	29.89	Direct	Form 4 ↗0001628280-26-052968
2026-08-01Filed 2026-08-04	SAINT FREDERICK G.Officer · President, Marketplaces Filing context Reported filing row; may be amended. Do not sum filings blindly. References:	F WithholdingCommon Stock, par value $0.01 per share · Non-derivative	1,436D	28.76	Direct	Form 4 ↗0001500076-26-000010
2026-08-01Filed 2026-08-04	Cann Cynthia CammettOfficer · Chief Accounting Officer Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock. F2 The restricted stock units vest in four equal installments on August 1, 2027, August 1, 2028, August 1, 2029, and August 1, 2030. References:	F WithholdingCommon Stock, par value $0.01 per share · Non-derivative	1,077D	28.76	Direct	Form 4 ↗0001472762-26-000010
2026-07-31Filed 2026-08-04	Rossmann Robin JackOfficer · Chief Financial Officer Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock. F2 The restricted stock units vest in three equal installments on August 1, 2027, August 1, 2028 and August 1, 2029. References: F1, F2	A Award / grantRestricted Stock Units · Derivative	34,771A	0	Direct	Form 4 ↗0002146463-26-000005
2026-07-31Filed 2026-08-04	Cann Cynthia CammettOfficer · Chief Accounting Officer Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 Each restricted stock unit represents a contingent right to receive one share of CoStar Group, Inc. common stock. F2 The restricted stock units vest in four equal installments on August 1, 2027, August 1, 2028, August 1, 2029, and August 1, 2030. References: F1, F2	A Award / grantRestricted Stock Units · Derivative	26,078A	0	Direct	Form 4 ↗0001472762-26-000010
2026-07-01Filed 2026-07-06	LOWN CHRISTIAN M.Officer · Chief Financial Officer Filing context Reported filing row; may be amended. Do not sum filings blindly. References:	F WithholdingCommon Stock, par value $0.01 per share · Non-derivative	5,597D	29.36	Direct	Form 4 ↗0001701994-26-000006
2026-06-23Filed 2026-06-24	Sams Louise SDirector Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 The restricted stock award vests in full on the earlier of either the first anniversary of the grant date or the date of the Company's 2027 Annual Meeting of Stockholders. References: F1	A Award / grantCommon Stock, par value $0.01 per share · Non-derivative	8,262A	0	Direct	Form 4 ↗0001796961-26-000004
2026-06-23Filed 2026-06-24	Brunner Angelique G.Director Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 The restricted stock award vests in full on the earlier of either the first anniversary of the grant date or the date of the Company's 2027 Annual Meeting of Stockholders. References: F1	A Award / grantCommon Stock, par value $0.01 per share · Non-derivative	8,262A	0	Direct	Form 4 ↗0001742356-26-000002
2026-06-23Filed 2026-06-24	McCarthy Christine MDirector Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 The restricted stock award vests in full on the earlier of either the first anniversary of the grant date or the date of the Company's 2027 Annual Meeting of Stockholders. F2 This amount includes shares that were inadvertently omitted from the insider's prior filing. References: F1, F2	A Award / grantCommon Stock, par value $0.01 per share · Non-derivative	8,262A	0	Direct	Form 4 ↗0001628280-26-045326
2026-06-23Filed 2026-06-24	Glaser Rachel CDirector Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 The restricted stock award vests in full on the earlier of either the first anniversary of the grant date or the date of the Company's 2027 Annual Meeting of Stockholders. References: F1	A Award / grantCommon Stock, par value $0.01 per share · Non-derivative	8,262A	0	Direct	Form 4 ↗0001497570-26-000011
2026-06-23Filed 2026-06-24	BERISFORD JOHN LDirector Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 The restricted stock award vests in full on the earlier of either the first anniversary of the grant date or the date of the Company's 2027 Annual Meeting of Stockholders. References: F1	A Award / grantCommon Stock, par value $0.01 per share · Non-derivative	8,262A	0	Direct	Form 4 ↗0001449719-26-000002
2026-06-23Filed 2026-06-24	Musslewhite Robert WDirector Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 The restricted stock award vests in full on the earlier of either the first anniversary of the grant date or the date of the Company's 2027 Annual Meeting of Stockholders. References: F1	A Award / grantCommon Stock, par value $0.01 per share · Non-derivative	8,262A	0	Direct	Form 4 ↗0001390194-26-000002
2026-06-23Filed 2026-06-24	Hill John WDirector Filing context Reported filing row; may be amended. Do not sum filings blindly. F1 The restricted stock award vests in full on the earlier of either the first anniversary of the grant date or the date of the Company's 2027 Annual Meeting of Stockholders. References: F1	A Award / grantCommon Stock, par value $0.01 per share · Non-derivative	8,262A	0	Direct	Form 4 ↗0001351689-26-000002
2026-06-15Filed 2026-06-16	Cann Cynthia CammettOfficer · Chief Accounting Officer Filing context Reported filing row; may be amended. Do not sum filings blindly. References:	F WithholdingCommon Stock, par value $0.01 per share · Non-derivative	461D	32.04	Direct	Form 4 ↗0001472762-26-000008

Imported instruments only. Joint owners do not multiply transactions. Amendments are separate filing rows, not additional trades. No aggregate trade totals are implied.