CoStar Group CSGP
CoStar Group is the 458th largest S&P 500 company by market cap, worth $13.7 billion. 9 directors have filed with the SEC in the last 12 months (who counts), 1 of them an executive. 7 other officers are on file. At 30 Jun 2026, Vanguard was its largest institutional holder, with 16.9% of the company.
- CEO
- Andrew C. Florance
- Sector
- Real Estate
- Sub-industry
- Real Estate Services
- Headquarters
- Washington, D.C.
- Founded
- 1987
- More
- Wikipedia
- Market cap
- $13.7B
- 458th largest, 23 Oct 2026 close
- Price to sales
- 4.2
- Less useful for REITs
- Employees
- 8,000
- REIT: property staff may not be counted
- Market cap per employee
- $1.7M
- Not comparable for REITs
- Connections
- 3
- S&P 500 companies sharing a director or officer
Largest institutional holders
Each fund group's share of CoStar Group. Where a company has several share classes, the share is of its total value.
13F filings for the quarter to 30 Jun 2026
Board and officers
3 people here also hold roles at other S&P 500 companies.
Roles filed up to 30 Sep 2026
| Name | Title |
|---|---|
| Directors (9) | |
| Andrew C. FloranceFounder and CEO | |
| Nana BanerjeeDirectorLast filed 17 Mar 2026 | |
| John L. BerisfordDirector | |
| Angelique G. BrunnerDirector | |
| Rachel C. GlaserDirector | |
| John W. HillDirector | |
| Christine M. McCarthyDirectorAlso at Procter & Gamble | |
| Robert W. MusslewhiteDirectorAlso at Cardinal Health | |
| Louise S. SamsDirectorAlso at Rollins | |
| Officers (7) | |
| Robin Jack RossmannChief Financial OfficerLast filed 4 Aug 2026 | |
| Gene BoxerGeneral Counsel and SecretaryLast filed 17 Mar 2026 | |
| Cynthia Cammett CannChief Accounting OfficerLast filed 10 Aug 2026 | |
| Michael J. DesmaraisChief Human Resources OfficerLast filed 17 Mar 2026 | |
| Lisa RugglesSenior VP, Global OperationsLast filed 17 Mar 2026 | |
| Frederick G. SaintPresident, MarketplacesLast filed 4 Aug 2026 | |
| Frank SimuroChief Technology OfficerLast filed 17 Mar 2026 | |
Companies that share people with CoStar Group
Each person's title here, then at the other company.
- Cardinal Health CAH
- Robert W. Musslewhite: Director here, Director there
- Procter & Gamble PG
- Christine M. McCarthy: Director here, Director there
- Rollins ROL
- Louise S. Sams: Director here, Director there
CoStar Group's market cap since December 2008
Marked weeks are changes in the share count, such as a merger, not market moves.
Weekly, up to 23 Oct 2026
| Week ending | Market cap |
|---|---|
| 23 Oct 2026 | $13.7B |
| 26 Dec 2025 | $28.4B |
| 27 Dec 2024 | $29.6B |
| 29 Dec 2023 | $35.7B |
| 30 Dec 2022 | $31.4B |
| 31 Dec 2021 | $31.2B |
| 25 Dec 2020 | $35.7B |
| 27 Dec 2019 | $21.9B |
| 28 Dec 2018 | $12.3B |
| 29 Dec 2017 | $10.7B |
| 30 Dec 2016 | $6.1B |
| 25 Dec 2015 | $6.8B |
| 26 Dec 2014 | $6.1B |
| 27 Dec 2013 | $5.3B |
| 28 Dec 2012 | $2.5B |
| 30 Dec 2011 | $1.7B |
| 31 Dec 2010 | $1.2B |
| 25 Dec 2009 | $840M |
| 26 Dec 2008 | $610M |
Download CoStar Group's data as JSON, with the weekly market caps in billions of dollars from 5 Dec 2008.
Workforce
Headcount at 31 Dec 2025
- Employees
- 8,000
With over 8,000 employees in 20 countries, our business is built on delivering excellence and innovation to our clients and supporting a workplace where our people can thrive.
Insider trades
Open-market buys and sales by directors and officers. Grants, option exercises and shares withheld for tax are left out.
Trades from 30 Sep 2025 to 30 Sep 2026
Directors and officers sold $534,282 of stock in 4 sales and bought $8.5 million in 6 purchases in the 12 months to 30 Sep 2026.
| Date | Person | Value |
|---|---|---|
| 7 Aug 2026Sale | Cynthia Cammett CannChief Accounting Officer | $147K |
| 5 Aug 2026Sale | John W. HillDirector | $106K |
| 4 Aug 2026Buy | Andrew C. FloranceFounder and CEO | $2.5M |
| 1 May 2026Buy | Andrew C. FloranceFounder and CEO | $2.5M |
| 6 Mar 2026Buy | Louise S. SamsDirector | $48K |
| 2 Mar 2026Buy | Frederick G. SaintPresident, Marketplaces | $907K |
| 2 Mar 2026Buy | Rachel C. GlaserDirector | $45K |
| 27 Feb 2026Buy | Andrew C. FloranceFounder and CEO | $2.5M |
| 13 Nov 2025Sale | John W. HillDirector | $155K |
| 13 Nov 2025Sale | Cynthia Cammett CannChief Accounting Officer | $127K |
Trades by members of Congress and officials
Trades members of Congress and senior executive branch officials disclosed, including their families'. Amounts are filed as ranges.
Trades from 20 Oct 2023 to 20 Oct 2026
9 people disclosed 30 purchases and 23 sales of CoStar Group stock since October 2023.
| Date | Member or official | Amount |
|---|---|---|
| 19 Aug 2026 | Gilbert CisnerosHouse, D-CA 路 Bought | $1K to $15K |
| 23 Jun 2026 | Donald J TrumpPresident 路 Sold | $1K to $15K |
| 18 Jun 2026 | Donald J TrumpPresident 路 Sold | $100K to $250K |
| 3 Jun 2026 | Donald J TrumpPresident 路 Bought | $1K to $15K |
| 22 May 2026 | Donald J TrumpPresident 路 Bought | $50K to $100K |
| 18 May 2026 | Donald J TrumpPresident 路 Bought | $1K to $15K |
| 28 Apr 2026 | Donald J TrumpPresident 路 Sold | $1K to $15K |
| 20 Apr 2026 | Donald J TrumpPresident 路 Sold | $50K to $100K |
| 17 Apr 2026 | Donald J TrumpPresident 路 Bought | $100K to $250K |
| 17 Apr 2026 | Donald J TrumpPresident 路 Sold | $1K to $15K |
Showing 10 of 53 trades
WARN layoff notices
Notices filed under CoStar Group's own name. Subsidiaries that file under their own names are not included.
Notices from 26 Oct 2023 to 26 Oct 2026
CoStar Group filed 1 notice covering 3 workers since October 2023.
| Notice | Place | Workers |
|---|---|---|
| 11 Nov 2025 | Atlanta, GA | 3 |