CoStar Group, Inc. Insider Trading

CSGP

Last 12 months

Insiders bought $8.48M and sold 534K on the open market.

None of the selling was scheduled in advance under a 10b5-1 plan. Director John W Hill sold 155K on Nov 13, 2025, 11% of their stake, outside a plan.

Net open-market

+$7.95M

6 buys · 4 sales

Under a 10b5-1 plan

of the value sold

Insiders who bought / sold

4 / 2

executives and directors

Last open-market buy

Aug 2026

Aug 4, 2026

Get an email when CSGP's executives or directors buy, or make a large sale outside a plan.

Trades · last 2 years

Date	Insider	Trade	Shares	Price	Value	Of their stake	Filing
Aug 7	Cynthia Cammett Cann Chief Accounting Officer	SoldNo plan	4,788	$30.78	147K	20%	Form 4
Aug 5	John W Hill Director	SoldNo plan	3,500	$30.21	106K	13%	Form 4
Aug 4	Andrew C Florance Founder and CEO	Bought	83,300	$29.89	$2.49M	4.8%	Form 4
May 1	Andrew C Florance President and CEO	Bought 2 parts	71,430	$35.20 average	$2.51M	4.3%	Form 4
Mar 6	Louise S Sams Director	Bought	1,000	$48.36	48K	5.2%	Form 4
Mar 2	Frederick G. Saint President, Marketplaces	Bought	20,000	$45.33	907K	7.7%	Form 4
Mar 2	Rachel C Glaser Director	Bought	1,000	$44.94	45K	32%	Form 4
Feb 27	Andrew C Florance President and CEO	Bought	55,720	$44.52	$2.48M	3.6%	Form 4
Nov 13, 2025	John W Hill Director	SoldNo plan	2,250	$68.68	155K	11%	Form 4
Nov 13, 2025	Cynthia Cammett Cann Chief Accounting Officer	SoldNo plan	1,841	$68.79	127K	7.3%	Form 4
Aug 28, 2025	Frederick G. Saint President, Marketplaces	SoldNo plan	25,000	$90.33	$2.26M	7.9%	Form 4
Jul 28, 2025	Frederick G. Saint President, Marketplaces	SoldNo plan	25,000	$93.23	$2.33M	7.3%	Form 4
Jul 28, 2025	Cynthia Cammett Cann Chief Accounting Officer	SoldNo plan	2,033	$92.85	189K	7.3%	Form 4
Jun 11, 2025	Frederick G. Saint President, Marketplaces	SoldNo plan	25,000	$81.10	$2.03M	6.8%	Form 4
Nov 11, 2024 – Mar 10, 2025	Cynthia Cammett Cann Chief Accounting Officer	SoldNo plan 2 parts	3,059	$78.59 average	240K	9.4%	Form 4
Dec 10, 2024	John W Hill Director	SoldNo plan	2,735	$76.76	210K	14%	Form 4
Nov 27, 2024	Christopher J Nassetta Director	SoldNo plan	1,681	$80.39	135K	0.6%	Form 4
Nov 26, 2024	Michael J Desmarais Chief Human Resources Officer	SoldNo plan	5,500	$79.88	439K	8.6%	Form 4

Aug 7No plan
Cynthia Cammett Cann
Chief Accounting Officer · sold 4,788 at $30.78
147K
20% of stake
Aug 5No plan
John W Hill
Director · sold 3,500 at $30.21
106K
13% of stake
Aug 4
Andrew C Florance
Founder and CEO · bought 83,300 at $29.89
$2.49M
4.8% of stake
May 1
Andrew C Florance
President and CEO · bought 71,430 at avg $35.20
$2.51M
4.3% of stake
Mar 6
Louise S Sams
Director · bought 1,000 at $48.36
48K
5.2% of stake
Mar 2
Frederick G. Saint
President, Marketplaces · bought 20,000 at $45.33
907K
7.7% of stake
Mar 2
Rachel C Glaser
Director · bought 1,000 at $44.94
45K
32% of stake
Feb 27
Andrew C Florance
President and CEO · bought 55,720 at $44.52
$2.48M
3.6% of stake
Nov 13, 2025No plan
John W Hill
Director · sold 2,250 at $68.68
155K
11% of stake
Nov 13, 2025No plan
Cynthia Cammett Cann
Chief Accounting Officer · sold 1,841 at $68.79
127K
7.3% of stake
Aug 28, 2025No plan
Frederick G. Saint
President, Marketplaces · sold 25,000 at $90.33
$2.26M
7.9% of stake
Jul 28, 2025No plan
Frederick G. Saint
President, Marketplaces · sold 25,000 at $93.23
$2.33M
7.3% of stake
Jul 28, 2025No plan
Cynthia Cammett Cann
Chief Accounting Officer · sold 2,033 at $92.85
189K
7.3% of stake
Jun 11, 2025No plan
Frederick G. Saint
President, Marketplaces · sold 25,000 at $81.10
$2.03M
6.8% of stake
Nov 11, 2024 – Mar 10, 2025No plan
Cynthia Cammett Cann
Chief Accounting Officer · sold 3,059 at avg $78.59
240K
9.4% of stake
Dec 10, 2024No plan
John W Hill
Director · sold 2,735 at $76.76
210K
14% of stake
Nov 27, 2024No plan
Christopher J Nassetta
Director · sold 1,681 at $80.39
135K
0.6% of stake
Nov 26, 2024No plan
Michael J Desmarais
Chief Human Resources Officer · sold 5,500 at $79.88
439K
8.6% of stake

How to read this. Insiders sell for many reasons: taxes, diversifying, a house. Open-market buys are rarer and say more. A 10b5-1 plan is a trading schedule set up months in advance, so those sales were not timed on news. Large holders (funds and 10% owners) are listed under Everything but not counted as insiders. If you own or watch CSGP, we send a push when an executive buys or makes a large sale outside a plan.

Source: SEC Form 4 filings, filed within two business days of each trade and checked for new ones every hour.

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Held by ETFs

CSGP is in 185 US ETFs. The largest of them, with CSGP's weight in each:

Spot a number that looks wrong? Check it in CSGP's SEC filings or

Download this analysis as a PDF (Pro)

Data sourced from SEC EDGAR filings and third-party price providers. Scores, valuations, and metrics are algorithmic estimates. This is not investment advice. See our Terms and Methodology.

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