CoStar Group, Inc. (CSGP) Insider Trading
Over the last 3 months, CSGP insiders made 1 open-market buy and 2 sales, a net purchase of $2.2M (SEC Form 4). Over the last 6 months, 610 institutions increased and 554 reduced their position (13F).
Insider Activity
Sentiment
92/100
Buys (3m)
1
Sells (3m)
2
Net (3m)
$2.2M
Insiders buyingFirst buy in 1 quarters
Insider trades by month Buys Sells
Jul
Sep
Nov
Mar
May
Aug
Context3-month price -5.6%Institutions accumulating (13F)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| Aug 10, 2026 | Cann Cynthia Cammettofficer: Chief Accounting Officer | Sell | 4,788 | $30.78 |
| Aug 10, 2026 | Hill John Wdirector | Sell | 3,500 | $30.21 |
| Aug 5, 2026 | FLORANCE ANDREW Cdirector, officer: Founder and CEO | Buy | 83,300 | $29.89 |
| Aug 4, 2026 | Cann Cynthia Cammettofficer: Chief Accounting Officer | Tax | 1,077 | $28.76 |
| Aug 4, 2026 | Rossmann Robin Jackofficer: Chief Financial Officer | Grant | 34,771 | — |
| Aug 4, 2026 | SAINT FREDERICK G.officer: President, Marketplaces | Tax | 1,436 | $28.76 |
| Aug 4, 2026 | Cann Cynthia Cammettofficer: Chief Accounting Officer | Grant | 26,078 | — |
| Jul 6, 2026 | LOWN CHRISTIAN M.officer: Chief Financial Officer | Tax | 5,597 | $29.36 |
| Jun 24, 2026 | Musslewhite Robert Wdirector | Grant | 8,262 | — |
| Jun 24, 2026 | Hill John Wdirector | Grant | 8,262 | — |
| Jun 24, 2026 | Brunner Angelique G.director | Grant | 8,262 | — |
| Jun 24, 2026 | McCarthy Christine Mdirector | Grant | 8,262 | — |
| Jun 24, 2026 | Sams Louise Sdirector | Grant | 8,262 | — |
| Jun 24, 2026 | Glaser Rachel Cdirector | Grant | 8,262 | — |
| Jun 24, 2026 | BERISFORD JOHN Ldirector | Grant | 8,262 | — |
| Jun 16, 2026 | Cann Cynthia Cammettofficer: Chief Accounting Officer | Tax | 461 | $32.04 |
| May 4, 2026 | FLORANCE ANDREW Cdirector, officer: President and CEO | Buy | 3,100 | $35.82 |
| May 4, 2026 | FLORANCE ANDREW Cdirector, officer: President and CEO | Buy | 68,330 | $35.17 |
| Mar 17, 2026 | SIMURO FRANKofficer: Chief Technology Officer | Tax | 11,107 | $43.63 |
| Mar 17, 2026 | Ruggles Lisaofficer: Senior VP, Global Operations | Tax | 2,977 | $43.63 |
| Mar 17, 2026 | Cann Cynthia Cammettofficer: Chief Accounting Officer | Tax | 1,194 | $43.63 |
| Mar 17, 2026 | Boxer Geneofficer: General Counsel and Secretary | Tax | 428 | $43.63 |
| Mar 17, 2026 | Boxer Geneofficer: General Counsel and Secretary | Tax | 482 | $43.63 |
| Mar 17, 2026 | DESMARAIS MICHAEL Jofficer: Chief Human Resources Officer | Tax | 2,873 | $43.63 |
| Mar 11, 2026 | LOWN CHRISTIAN M.officer: Chief Financial Officer | Grant | 12,268 | $46.34 |
| Mar 11, 2026 | Boxer Geneofficer: General Counsel and Secretary | Grant | 21,920 | $46.34 |
| Mar 11, 2026 | DESMARAIS MICHAEL Jofficer: Chief Human Resources Officer | Grant | 17,676 | $46.34 |
| Mar 11, 2026 | Cann Cynthia Cammettofficer: Chief Accounting Officer | Grant | 4,374 | $46.34 |
| Mar 11, 2026 | FLORANCE ANDREW Cdirector, officer: President and CEO | Grant | 124,162 | $46.34 |
| Mar 9, 2026 | Sams Louise Sdirector | Buy | 1,000 | $48.36 |
Source: CSGP SEC Form 4 filings, latest Aug 10, 2026. For informational purposes only — not investment advice.
Institutional activity (13F)
How institutions changed their CSGP positions over the last 6 months (SEC Form 13F).
Increased
610
New positions
247
Reduced
554
Sold out
145
Largest moves
| Institution | Action | Shares | Filed |
|---|---|---|---|
| VANGUARD PORTFOLIO MANAGEMENT LLC | New Position | 38.2M | May 8, 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Reduced | 37.9M | Aug 13, 2026 |
| BlackRock, Inc. | Increased | 33.8M | Aug 7, 2026 |
| BLACKROCK, INC. | Reduced | 33.8M | May 13, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | New Position | 27.4M | May 15, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | Reduced | 26.7M | Aug 13, 2026 |
| BAMCO INC /NY/ | Increased | 21.6M | Aug 14, 2026 |
| STATE STREET CORP | Increased | 18.7M | May 15, 2026 |
| STATE STREET CORP | Reduced | 18.4M | Aug 7, 2026 |
| PRINCIPAL FINANCIAL GROUP INC | Increased | 17.7M | May 4, 2026 |
| Capital International Investors | Increased | 16.6M | Aug 12, 2026 |
| BAMCO INC /NY/ | Reduced | 16.3M | May 15, 2026 |
| CAPITAL INTERNATIONAL INVESTORS | Increased | 15.5M | May 13, 2026 |
| BAILLIE GIFFORD & CO | Increased | 13.6M | May 8, 2026 |
| BAILLIE GIFFORD & CO | Reduced | 13.2M | Aug 6, 2026 |
Source: SEC Form 13F filings. For informational purposes only — not investment advice.