Company profile

Costar Group, Inc. Insider Trading

CSGP

Every SEC Form 4 insider trading filing for Costar Group, Inc. (CSGP) since April 2023 — open-market buys and sells by directors and officers, option exercises, and cluster activity, updated as each filing is reported to the SEC. Why 2023?

Exchange
Nasdaq
Sector
Services-Business Services, NEC
CIK
0001057352
Filings
164
Insiders
21
Last filing
2026-08-07
SEC EDGAR ↗Yahoo Finance ↗Finviz ↗Stock Analysis ↗

Activity summary

Recent insider activity is bearish. Over the last 30 days, insiders net sold $2.2M across 4 transactions, with 3 offsetting purchases.

Three year balance

Buy and sell value by quarter, Q4 23 to Q3 26. Costar Group, Inc. insiders are net sellers across the period shown.

Q4 23Q1 24Q2 24Q3 24Q4 24Q1 25Q2 25Q3 25Q4 25Q1 26Q2 26Q3 26

Bars below the rule are sales, above are purchases. Largest quarter on the chart is $13.8M.

90 day insight

Over the last 90 days, Costar Group, Inc. insiders bought $2.5M (10 transactions) and sold $504K (6 transactions).

  • Most active insider: Cann Cynthia Cammett with 4 transactions totaling $193K.
  • Largest single purchase: $2.5M by Florance Andrew C on Aug 4, 2026.

Activity skews bullish — buys outpace sales.

Insider Transactions

Sourced from SEC EDGAR Form 4 filings. Updated hourly.

DateInsiderCompanyTypeSharesPriceValue
Aug 7, 2026Cann Cynthia CammettCSGP
Sale
4,788$30.78$147K
Aug 5, 2026Hill John WCSGP
Sale
3,500$30.21$106K
Aug 4, 2026Florance Andrew CCSGP
Purchase
83,300$29.89$2.49M
Aug 1, 2026Cann Cynthia CammettCSGP
Tax Withholding
1,077$28.76$31K
Aug 1, 2026Saint Frederick G.CSGP
Tax Withholding
1,436$28.76$41K

45 more transactions hidden

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Query this yourself

The same rows, over the API.

curl "https://api.form4api.com/v1/transactions?ticker=CSGP" \
  -H "X-Api-Key: $KEY"
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Top insiders

By total value filed.

Florance Andrew CFounder and CEO5 filings+$4.8M
Saint Frederick G.President, Marketplaces4 filings+$265K
Simuro FrankChief Technology Officer2 filings−$1.3M
Ruggles LisaSenior VP, Global Research2 filings−$528K
Lown Christian M.Chief Financial Officer2 filings−$485K

Institutional Ownership

Top 13F-HR holders of Costar Group, Inc. as of 2026-06-30

↓ decreasing
Total reported AUM
$3.19B
QoQ change
-77.6%
Reporting period
2026-06-30
#1
State Street Corp
CIK 0000093751
$521.4M
18.4M shares
#2
BlackRock, Inc.
CIK 0002012383
$464.0M
16.4M shares
#3
Polen Capital Management LLC
CIK 0001034524
$248.1M
8.8M shares

Data source: quarterly 13F-HR filings — institutional holders report positions within 45 days of quarter end. Joined with insider activity above — see who's loading up institutionally while insiders are trading. Full 13F-HR API →