United States Software & IT Services

CoStar Group Inc (CSGP)

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Over the past 90 days, CoStar Group Inc. recorded two insider transactions. CEO Andrew C. Florance purchased shares valued at approximately $2.49 million on August 4, 2026. Conversely, Director John W. Hill filed a proposed sale of 3,500 shares valued at $106,067 on August 5, 2026, following the company's July 28, 2026, results financiers.
Ticker: CSGP Exchange: NSM
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• Purchase • Sale • Planned purchase • Planned sale Net purchase Net sale Buy signal Sell signal Earnings
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Proposed sale 5 Aug 2026
Value US$3,048,834.78 | Price 453.71 | Shares 93,906
Abbreviations B: Buy, S: Sell, PP: Planned purchase, PlS: Planned sale, PrS: Proposed sale, O: Option / Other
Notification date Transaction date B/S Transaction type Insider and/or position Nb. shares
Price
Value 		Number of shares Price Value Details
2026-08-05 2026-08-05 PrS Proposed sale
3.4
Hill John W

Director

Non-Executive Director
93,906
453.71
US$3,048,835 		93,906 453.71 US$3,048,835
2026-08-05 2026-08-04 B Purchase
2.8
FLORANCE ANDREW C

Founder and CEO

Executive Director
64,766 -19.9%
387.46
US$3,315,737 		64,766 -19.9% 387.46 US$3,315,737
2026-05-04 2026-05-01 B Purchase
2.8
FLORANCE ANDREW C

President and CEO

Executive Director
44,197 -36.0%
226.53
US$550,164 		44,197 -36.0% 226.53 US$550,164
2026-05-04 2026-05-01 B Purchase
2.8
FLORANCE ANDREW C

President and CEO

Executive Director
68,330 +4.1%
35.17
US$2,403,166 		68,330 +4.1% 35.17 US$2,403,166
2026-03-09 2026-03-06 B Purchase
0.6
Sams Louise S
Non-Executive Director
1,000 +5.2%
48.36
US$48,360 		1,000 +5.2% 48.36 US$48,360
2026-03-03 2026-03-02 B Purchase
2.8
SAINT FREDERICK G.

President, Marketplaces

Officer
20,000 +7.7%
45.33
US$906,600 		20,000 +7.7% 45.33 US$906,600
2026-03-03 2026-03-02 B Purchase
2.4
Glaser Rachel C
Non-Executive Director
1,000 +31.7%
44.94
US$44,940 		1,000 +31.7% 44.94 US$44,940
2026-03-02 2026-02-27 B Purchase
2.8
FLORANCE ANDREW C

President and CEO

Executive Director
55,720 +3.6%
44.52
US$2,480,654 		55,720 +3.6% 44.52 US$2,480,654
2025-11-17 2025-11-13 S Sale
3.5
Cann Cynthia Cammett

Chief Accounting Officer

Officer
1,841 -7.3%
68.79
US$126,642 		1,841 -7.3% 68.79 US$126,642
2025-11-17 2025-11-13 S Sale
3.4
Hill John W
Non-Executive Director
2,250 -11.0%
68.68
US$154,530 		2,250 -11.0% 68.68 US$154,530
2025-11-13 2025-11-13 PrS Proposed sale
3.4
Hill John W

Director; Member of immediate family of any of the foregoing

Non-Executive Director
2,250
67.52
US$151,920 		2,250 67.52 US$151,920
2025-09-02 2025-08-28 S Sale
2.8
SAINT FREDERICK G.

President, Marketplaces

Officer
25,000 -7.9%
90.33
US$2,258,250 		25,000 -7.9% 90.33 US$2,258,250
2025-08-28 2025-08-28 PrS Proposed sale
2.8
FREDERICK SAINT

Officer

Officer
25,000
90.33
US$2,258,225 		25,000 90.33 US$2,258,225
2025-07-29 2025-07-28 S Sale
2.8
SAINT FREDERICK G.

President, Marketplaces

Officer
25,000 -7.3%
93.23
US$2,330,750 		25,000 -7.3% 93.23 US$2,330,750
2025-07-29 2025-07-28 S Sale
3.5
Cann Cynthia Cammett

Chief Accounting Officer

Officer
2,033 -7.3%
92.85
US$188,764 		2,033 -7.3% 92.85 US$188,764
2025-07-28 2025-07-28 PrS Proposed sale
2.8
FREDERICK SAINT

Officer

Officer
25,000
93.23
US$2,330,828 		25,000 93.23 US$2,330,828
2025-06-12 2025-06-11 S Sale
2.8
SAINT FREDERICK G.

President, Marketplaces

Officer
25,000 -6.8%
81.10
US$2,027,500 		25,000 -6.8% 81.10 US$2,027,500
2025-06-11 2025-06-11 PrS Proposed sale
2.8
FREDERICK SAINT

Officer; Director

Executive Director
25,000
81.10
US$2,027,382 		25,000 81.10 US$2,027,382
2025-05-12 2025-05-12 PrS Proposed sale
2.5
Michael Klein

Former Board Member, retired less than 90 days ago
267,936
75.20
US$20,148,787 		267,936 75.20 US$20,148,787
2025-05-09 2025-05-09 PrS Proposed sale
2.5
Michael Klein

Former Board Member, retired less than 90 days ago
32,064
75.37
US$2,416,664 		32,064 75.37 US$2,416,664
2025-03-14 2025-03-10 S Sale
3.5
Cann Cynthia Cammett

Chief Accounting Officer

Officer
1,749 -5.6%
79.90
US$139,745 		1,749 -5.6% 79.90 US$139,745
2024-12-12 2024-12-10 S Sale
3.4
Hill John W
Non-Executive Director
2,735 -13.5%
76.76
US$209,939 		2,735 -13.5% 76.76 US$209,939
2024-12-10 2024-12-10 PrS Proposed sale
3.4
Hill John W

Director

Non-Executive Director
2,735
78.65
US$215,100 		2,735 78.65 US$215,100
2024-12-02 2024-11-27 S Sale
3.1
NASSETTA CHRISTOPHER J
Non-Executive Director
1,681 -0.7%
80.39
US$135,136 		1,681 -0.7% 80.39 US$135,136
2024-11-27 2024-11-27 PrS Proposed sale
3.1
Christopher J Nasseta

Director

Non-Executive Director
1,681
79.92
US$134,346 		1,681 79.92 US$134,346
2024-11-27 2024-11-26 PlS Planned sale
3.1
DESMARAIS MICHAEL J

Chief Human Resources Officer

Officer
5,500 -8.6%
79.88
US$439,340 		5,500 -8.6% 79.88 US$439,340
2024-11-26 2024-11-26 PrS Proposed sale
3.1
MICHAEL DESMARAIS

Officer

Officer
5,500
79.88
US$439,324 		5,500 79.88 US$439,324
2025-03-14 2024-11-11 S Sale
3.5
Cann Cynthia Cammett

Chief Accounting Officer

Officer
1,310 -4.7%
76.85
US$100,674 		1,310 -4.7% 76.85 US$100,674
2024-10-28 2024-10-25 B Purchase
2.8
FLORANCE ANDREW C

President and CEO

Executive Director
14,731 +1.2%
74.67
US$1,099,966 		14,731 +1.2% 74.67 US$1,099,966
2024-10-28 2024-10-25 S Sale
2.5
KLEIN MICHAEL R
Non-Executive Director
71,633 -3.6%
74.69
US$5,350,269 		71,633 -3.6% 74.69 US$5,350,269
2024-10-25 2024-10-25 PrS Proposed sale
2.5
Michael Klein

Director

Non-Executive Director
71,633
73.99
US$5,300,000 		71,633 73.99 US$5,300,000
2025-03-14 2024-07-31 S Sale
3.5
Cann Cynthia Cammett

Chief Accounting Officer

Officer
1,200 -4.1%
78.20
US$93,840 		1,200 -4.1% 78.20 US$93,840
2024-08-01 2024-07-30 S Sale
3.4
Hill John W
Non-Executive Director
1,325 -7.4%
78.16
US$103,562 		1,325 -7.4% 78.16 US$103,562
2024-07-30 2024-07-30 PrS Proposed sale
3.4
Hill John W

Director

Non-Executive Director
1,325
77.74
US$103,000 		1,325 77.74 US$103,000
2024-05-17 2024-05-16 S Sale
2.8
SAINT FREDERICK G.

President, Marketplaces

Officer
2,500 -0.9%
88.43
US$221,075 		2,500 -0.9% 88.43 US$221,075
2024-05-16 2024-05-16 PrS Proposed sale
2.8
FREDERICK SAINT

Officer

Officer
2,500
88.43
US$221,070 		2,500 88.43 US$221,070
2024-05-10 2024-05-09 S Sale
3.0
Ruggles Lisa

Senior VP, Global Operations

Officer
20,000 -10.4%
91.15
US$1,823,000 		20,000 -10.4% 91.15 US$1,823,000
2024-05-10 2024-05-09 S Sale
3.0
Ruggles Lisa

Senior VP, Global Operations

Officer
20,000 -10.4%
91.15
US$1,823,000 		20,000 -10.4% 91.15 US$1,823,000
2024-05-09 2024-05-09 PrS Proposed sale
3.0
LISA C. RUGGLES

Officer

Officer
20,000
91.15
US$1,822,922 		20,000 91.15 US$1,822,922
2024-04-30 2024-04-26 S Sale
3.1
DESMARAIS MICHAEL J

Chief Human Resources Officer

Officer
3,800 -5.6%
92.67
US$352,146 		3,800 -5.6% 92.67 US$352,146
2024-04-30 2024-04-26 S Sale
3.2
Wheeler Scott T

Chief Financial Officer

Officer
122,736 -28.8%
92.61
US$11,366,581 		122,736 -28.8% 92.61 US$11,366,581
2024-04-26 2024-04-26 PrS Proposed sale
3.2
SCOTT WHEELER

Officer

Officer
122,736
92.61
US$11,366,912 		122,736 92.61 US$11,366,912
2024-04-26 2024-04-26 PrS Proposed sale
3.1
MICHAEL DESMARAIS

Officer

Officer
3,800
92.67
US$352,155 		3,800 92.67 US$352,155
2023-11-29 2023-11-28 S Sale
3.4
Hill John W
Non-Executive Director
3,020 -14.5%
84.07
US$253,891 		3,020 -14.5% 84.07 US$253,891
2023-11-28 2023-11-28 PrS Proposed sale
3.4
Hill John W

Director

Non-Executive Director
3,020
82.78
US$250,000 		3,020 82.78 US$250,000
2023-11-09 2023-11-08 S Sale
3.1
NASSETTA CHRISTOPHER J
Non-Executive Director
1,500 -0.5%
77.86
US$116,790 		1,500 -0.5% 77.86 US$116,790
2023-11-08 2023-11-08 PrS Proposed sale
3.1
Christopher J Nassetta

Director

Non-Executive Director
1,500
77.87
US$116,798 		1,500 77.87 US$116,798
2023-06-28 2023-06-28 PrS Proposed sale
3.2
SCOTT WHEELER

Officer

Officer
21,530
89.30
US$1,922,696 		21,530 89.30 US$1,922,696
2023-06-28 2023-06-27 S Sale
3.1
SIMURO FRANK

Chief Technology Officer

Officer
92,300 -25.9%
89.65
US$8,274,695 		92,300 -25.9% 89.65 US$8,274,695
2023-06-27 2023-06-27 PrS Proposed sale
3.1
SIMURO FRANK

Officer

Officer
92,300
87.81
US$8,104,863 		92,300 87.81 US$8,104,863
2023-06-28 2023-06-26 S Sale
3.4
Hill John W
Non-Executive Director
1,500 -8.1%
86.57
US$129,855 		1,500 -8.1% 86.57 US$129,855
2023-06-23 2023-06-23 PrS Proposed sale
3.4
Hill John W

Director

Non-Executive Director
1,500
83.95
US$125,932 		1,500 83.95 US$125,932
2023-06-14 2023-06-12 S Sale
3.2
Wheeler Scott T

Chief Financial Officer

Officer
24,670 -6.7%
80.68
US$1,990,376 		24,670 -6.7% 80.68 US$1,990,376
2023-06-12 2023-06-12 PrS Proposed sale
3.2
SCOTT WHEELER

Officer

Officer
24,670
80.68
US$1,990,482 		24,670 80.68 US$1,990,482
2023-06-09 2023-06-07 S Sale
2.8
SAINT FREDERICK G.

President, Marketplaces

Officer
30,000 -11.2%
80.24
US$2,407,200 		30,000 -11.2% 80.24 US$2,407,200
2023-06-07 2023-06-07 PrS Proposed sale
2.8
FREDERICK SAINT

Officer

Officer
30,000
80.24
US$2,407,149 		30,000 80.24 US$2,407,149
2023-05-02 2023-04-28 S Sale
2.8
FLORANCE ANDREW C

President and CEO

Executive Director
360,530 -27.0%
76.77
US$27,677,888 		360,530 -27.0% 76.77 US$27,677,888
2023-04-28 2023-04-28 PrS Proposed sale
2.8
ANDREW FLORANCE

Officer; Director

Executive Director
360,530
76.77
US$27,677,708 		360,530 76.77 US$27,677,708
2023-04-04 2023-03-31 S Sale
3.4
Hill John W
Non-Executive Director
2,300 -11.1%
68.50
US$157,550 		2,300 -11.1% 68.50 US$157,550
2023-03-09 2023-03-08 S Sale
3.1
DESMARAIS MICHAEL J

Chief Human Resources Officer

Officer
5,600 -11.1%
70.36
US$394,016 		5,600 -11.1% 70.36 US$394,016
2023-03-03 2023-03-01 S Sale
3.1
SIMURO FRANK

Chief Technology Officer

Officer
35,220 -9.4%
70.09
US$2,468,570 		35,220 -9.4% 70.09 US$2,468,570
2022-11-04 2022-11-03 S Sale
3.4
Hill John W
Non-Executive Director
3,650 -15.0%
78.92
US$288,058 		3,650 -15.0% 78.92 US$288,058
2022-10-31 2022-10-28 S Sale
3.1
DESMARAIS MICHAEL J

Chief Human Resources Officer

Officer
1,296 -3.4%
82.81
US$107,322 		1,296 -3.4% 82.81 US$107,322
2022-08-11 2022-08-10 S Sale
3.4
Hill John W
Non-Executive Director
1,400 -6.4%
74.49
US$104,286 		1,400 -6.4% 74.49 US$104,286
2022-08-09 2022-08-05 S Sale
2.5
KLEIN MICHAEL R
Non-Executive Director
150,000 -6.7%
72.42
US$10,863,000 		150,000 -6.7% 72.42 US$10,863,000
2022-08-05 2022-08-03 S Sale
3.1
DESMARAIS MICHAEL J

Chief Human Resources Officer

Officer
2,000 -4.8%
72.51
US$145,020 		2,000 -4.8% 72.51 US$145,020
2022-05-26 2022-05-24 S Sale
3.4
Hill John W
Non-Executive Director
1,750 -7.4%
57.07
US$99,872 		1,750 -7.4% 57.07 US$99,872
2022-05-04 2022-05-02 S Sale
3.1
DESMARAIS MICHAEL J

Chief Human Resources Officer

Officer
1,000 -2.3%
63.14
US$63,140 		1,000 -2.3% 63.14 US$63,140
2022-03-03 2022-03-02 S Sale
3.0
Ruggles Lisa

Senior VP, Global Research

Officer
21,640 -11.8%
59.88
US$1,295,803 		21,640 -11.8% 59.88 US$1,295,803
2021-11-15 2021-11-11 S Sale
3.2
Wheeler Scott T

Chief Financial Officer

Officer
85 -11.6%
81.72
US$6,946 		85 -11.6% 81.72 US$6,946
2021-11-12 2021-11-10 S Sale
3.1
NASSETTA CHRISTOPHER J
Non-Executive Director
2,120 -0.8%
83.21
US$176,405 		2,120 -0.8% 83.21 US$176,405
2021-11-08 2021-11-05 S Sale
3.0
Kaplan Laura Cox
Non-Executive Director
4,040 -36.1%
83.29
US$336,492 		4,040 -36.1% 83.29 US$336,492
2021-11-02 2021-10-29 S Sale
3.4
Hill John W
Non-Executive Director
9,235 -27.9%
86.97
US$803,170 		9,235 -27.9% 86.97 US$803,170
2021-05-03 2021-04-30 S Sale
3.0
Kaplan Laura Cox
Non-Executive Director
1,062 -56.1%
869.03
US$922,910 		1,062 -56.1% 869.03 US$922,910
2021-03-25 2021-03-23 S Sale
2.8
SAINT FREDERICK G.

President, Marketplaces

Officer
7,834 -24.5%
831.70
US$6,515,538 		7,834 -24.5% 831.70 US$6,515,538
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