NASDAQ:CSGP

Costar Group Stock Insider Trading

Real Estate > Real Estate - Services

Buy CSGP

*Your capital is at risk

$33.40

-0.260 (-0.772%)

At Close: Jun 03, 2026

CoStar Group Stock Insider Power

Based on the 100 latest insides trades, we have calculated the insider power to be negative at -9.06. In total, the insiders bought 668.92K and sold 567.31K CSGP shares in the last 100 trades. The insider score can be negative despite buy/sell ratio being positive. The score focuses on the quality of the trades.

Insider Power (Last 100 transactions)	-9.06
● Buy	668.92K shares
● Sell	567.31K shares
41% Buy Activity Negligible or No Correlation
Buy Signal Low Confidence May 01, 2026 Analysis Breakdown: Weakened by a contradictory negative Insider Power Score. Confidence increased due to high data reliability score of 100.

Historical Insider Trades

Date	Type	Person	Role	Amount
Feb 27, 2026 Buy	Restricted Stock Units A-Award	Ruggles Lisa Senior Vp, Global Operations	Officer	28 197 Value: $1.26M
Feb 27, 2026 Buy	Restricted Stock Units A-Award	Cann Cynthia Cammett Chief Accounting Officer	Officer	6 834 Value: $305.0K
Feb 27, 2026 Buy	Restricted Stock Units A-Award	Desmarais Michael J Chief Human Resources Officer	Officer	17 926 Value: $800.0K
Feb 27, 2026 Buy	Restricted Stock Units A-Award	Boxer Gene General Counsel And Secretary	Officer	26 888 Value: $1.20M
Feb 27, 2026 Buy	Restricted Stock Units A-Award	Florance Andrew C President And CEO	CEO / President	83 708 Value: $3.74M
Feb 27, 2026 Buy	Restricted Stock Units A-Award	Lown Christian M. Chief Financial Officer	C-Suite Officer	39 652 Value: $1.77M
Feb 27, 2026 Buy	Restricted Stock Units A-Award	Saint Frederick G. President, Marketplaces	CEO / President	39 652 Value: $1.77M
Feb 27, 2026 Buy	Restricted Stock Units A-Award	Simuro Frank Chief Technology Officer	Officer	52 869 Value: $2.36M
Feb 27, 2026 Buy	Common Stock, par value $0.01 per share P-Purchase	Florance Andrew C President And CEO	CEO / President	55 720 Value: $2.48M
Feb 19, 2026 Sell	Common Stock, par value $0.01 per share D-Return	Saint Frederick G. President, Marketplaces	CEO / President	17 583 Value: $0
Feb 19, 2026 Sell	Common Stock, par value $0.01 per share D-Return	Simuro Frank Chief Technology Officer	Officer	30 727 Value: $0
Feb 19, 2026 Sell	Common Stock, par value $0.01 per share F-InKind	Simuro Frank Chief Technology Officer	Officer	4 421 Value: $216.9K
Feb 19, 2026 Sell	Common Stock, par value $0.01 per share F-InKind	Saint Frederick G. President, Marketplaces	CEO / President	2 149 Value: $105.5K
Feb 19, 2026 Sell	Common Stock, par value $0.01 per share D-Return	Florance Andrew C President And CEO	CEO / President	104 983 Value: $0
Feb 19, 2026 Sell	Common Stock, par value $0.01 per share F-InKind	Florance Andrew C President And CEO	CEO / President	19 221 Value: $943.2K
Feb 19, 2026 Sell	Common Stock, par value $0.01 per share D-Return	Ruggles Lisa Senior Vp, Global Operations	Officer	17 583 Value: $0
Feb 19, 2026 Sell	Common Stock, par value $0.01 per share F-InKind	Ruggles Lisa Senior Vp, Global Operations	Officer	3 219 Value: $158.0K
Feb 15, 2026 Sell	Common Stock, par value $0.01 per share F-InKind	Saint Frederick G. President, Marketplaces	CEO / President	2 424 Value: $109.1K
Feb 15, 2026 Sell	Common Stock, par value $0.01 per share F-InKind	Florance Andrew C President And CEO	CEO / President	17 482 Value: $786.5K
Feb 15, 2026 Sell	Common Stock, par value $0.01 per share F-InKind	Simuro Frank Chief Technology Officer	Officer	4 151 Value: $186.8K
Feb 15, 2026 Sell	Common Stock, par value $0.01 per share F-InKind	Ruggles Lisa Senior Vp, Global Operations	Officer	3 576 Value: $160.9K
Nov 13, 2025 Sell	Common Stock, par value $0.01 per share S-Sale	Cann Cynthia Cammett Chief Accounting Officer	Officer	1 841 Value: $126.6K
Nov 13, 2025 Sell	Common Stock, par value $0.01 per share S-Sale	Hill John W Director	Director	2 250 Value: $154.5K
Sep 09, 2025 Buy	Common Stock, par value $0.01 per share A-Award	Mccarthy Christine M Director	Director	2 973 Value: $262.0K
Sep 09, 2025 Buy	Common Stock, par value $0.01 per share A-Award	Sams Louise S Director	Director	3 291 Value: $290.1K

About Insider Power

Insider Power is a proprietary algorithm developed by StockInvest.us to evaluate the significance of insider transactions. The calculation considers the size, type, and timing of transactions, as well as the insider’s role within the company.

It is important to note that, in general, there is little to no correlation between insider transactions and short-term stock price movements. In one of our studies, only 0.22%^* of stocks with insider activity showed a measurable correlation — and even then, it was unclear whether the effect was caused by insider actions or simply by the stock’s broader trend.

While our algorithms are designed to highlight potentially meaningful signals, these cannot be regarded as statistically significant on their own. Insider trading activity should therefore be seen as informative rather than as direct trading guidance. The Insider Power metric was created to present this information in a clearer and more accessible way, helping investors better understand the possible context of insider activity.

* October 6th, 2025 - Tested on 5562 stocks

ABOUT COSTAR GROUP

CoStar Group, Inc. provides information, analytics, and online marketplace services to the commercial real estate, hospitality, residential, and related professionals industries in the United States, Canada, Europe, the Asia Pacific, and Latin America. It offers CoStar Property that provides inventory of office, industrial, retail, multifamily, hospitality, and student housing properties and land; CoStar COMPS, a robust database of comparable com...

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