Costar CSGP Insider Ownership

NASDAQ CSGP
$29.58 -0.76 (-2.50%)
As of: Sep 9, 2026 · 3:59 PM EDT

Insider Holdings by Owner

3.55Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026
Insider Ownership
0.430%
+0.020% pp QoQ
Shares Held by Insiders
1.81Mn
filed for Sep 2026
+4.83% QoQ
Shares Outstanding
419.90Mn
419,900,000 shares
Direct Holdings
1.81Mn
Indirect: 0
Net Shares Traded (QoQ)
+83.30K
net buying in Sep 2026
Insiders Holding Shares
16
with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding
Latest
Average ownership
Peak ownership

Shares Purchased/Sold by Insiders

Bought Sold
Latest quarter
Net over range
Buying quarters

Insider Ownership Summary

Quarter ending 30 Sep, 2026

CSGP's three largest insider shareholders as of September 09, 2026 are Andrew C Florance (Founder And Ceo, 1.81Mn shares), Frank Simuro (Chief Technology Officer, 414.49K shares), Frank Simuro (Chief Technology Officer, 414.49K shares).

Form 4 Holdings

Insiders Holding CSGP

Insiders 16
Shares held 3.55Mn
Of outstanding 0.845%
# Insider Position Direct Indirect Total Share of Insiders Last Filed
1 Andrew C Florance Founder And Ceo 1,806,165 0 1,806,165 50.9% 05 Aug, 2026
2 Frank Simuro Chief Technology Officer 414,491 0 414,491 11.7% 17 Mar, 2026
3 Scott T Wheeler Chief Financial Officer 303,417 0 303,417 8.6% 30 Apr, 2024
4 Frederick G. Saint President, Marketplaces 278,415 0 278,415 7.8% 04 Aug, 2026
5 Christopher J Nassetta Director 229,715 0 229,715 6.5% 02 Dec, 2024
6 Lisa Ruggles Senior Vp, Global Operations 174,915 0 174,915 4.9% 17 Mar, 2026
7 Gene Boxer General Counsel And Secretary 95,463 0 95,463 2.7% 17 Mar, 2026
8 Michael J Desmarais Chief Human Resources Officer 87,725 0 87,725 2.5% 17 Mar, 2026
9 Louise S Sams Director 28,671 0 28,671 0.8% 24 Jun, 2026
10 Robert W Musslewhite Director 26,539 0 26,539 0.7% 24 Jun, 2026
11 John W Hill Director 22,993 0 22,993 0.6% 10 Aug, 2026
12 Cynthia Cammett Cann Chief Accounting Officer 18,822 0 18,822 0.5% 10 Aug, 2026
13 Angelique G. Brunner Director 18,428 0 18,428 0.5% 24 Jun, 2026
14 Laura Cox Kaplan Director 17,835 0 17,835 0.5% 05 Aug, 2024
15 Rachel C Glaser Director 12,419 0 12,419 0.4% 24 Jun, 2026
16 John L Berisford Director 11,235 0 11,235 0.3% 24 Jun, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

2,897 Insider Transactions

Source SEC Form 4
Latest quarter Sep 2026
Download Data
Date Insider Position Transaction Shares Price Value Shares Held After Ownership
05 Aug, 2026 John W Hill Director Disposed S 3,500 $30.21 $105.74K 22,993 Direct
07 Aug, 2026 Cynthia Cammett Cann Chief Accounting Officer Disposed S 4,788 $30.78 $147.37K 18,822 Direct
04 Aug, 2026 Andrew C Florance Founder And Ceo Acquired P 83,300 $29.89 $2.49Mn 1,806,165 Direct
01 Aug, 2026 Frederick G. Saint President, Marketplaces Disposed F 1,436 $28.76 $41.30K 278,415 Direct
01 Aug, 2026 Cynthia Cammett Cann Chief Accounting Officer Disposed F 1,077 $28.76 $30.97K 23,610 Direct
31 Jul, 2026 Robin Jack Rossmann Chief Financial Officer Acquired A 34,771 $0.00 $0 34,771 Direct
31 Jul, 2026 Cynthia Cammett Cann Chief Accounting Officer Acquired A 26,078 $0.00 $0 26,078 Direct
23 Jun, 2026 Rachel C Glaser Director Acquired A 8,262 $0.00 $0 12,419 Direct
23 Jun, 2026 Louise S Sams Director Acquired A 8,262 $0.00 $0 28,671 Direct
23 Jun, 2026 John L Berisford Director Acquired A 8,262 $0.00 $0 11,235 Direct
23 Jun, 2026 Robert W Musslewhite Director Acquired A 8,262 $0.00 $0 26,539 Direct
23 Jun, 2026 John W Hill Director Acquired A 8,262 $0.00 $0 26,493 Direct
23 Jun, 2026 Angelique G. Brunner Director Acquired A 8,262 $0.00 $0 18,428 Direct
15 Jun, 2026 Cynthia Cammett Cann Chief Accounting Officer Disposed F 461 $32.04 $14.77K 24,687 Direct
01 May, 2026 Andrew C Florance President And Ceo Acquired P 68,330 $35.17 $2.40Mn 1,719,765 Direct
01 May, 2026 Andrew C Florance President And Ceo Acquired P 3,100 $35.82 $111.04K 1,722,865 Direct
15 Mar, 2026 Michael J Desmarais Chief Human Resources Officer Disposed F 2,873 $43.63 $125.35K 87,725 Direct
15 Mar, 2026 Lisa Ruggles Senior Vp, Global Operations Disposed F 2,977 $43.63 $129.89K 174,915 Direct
15 Mar, 2026 Michael J Desmarais Chief Human Resources Officer Disposed F 2,873 $43.63 $125.35K 87,725 Direct
15 Mar, 2026 Lisa Ruggles Senior Vp, Global Operations Disposed F 2,977 $43.63 $129.89K 174,915 Direct