Stock Trading Canary

United States · SEC Form 4 · Snapshot date: 2026-10-18 · Built: 2026-10-18 · 中文

← United States · Coverage record

US · SEC FORM 4

COSTAR GROUP, INC.

CSGP · Nasdaq · CIK 0001057352 · Real Estate · Real Estate Services

INSIDER SIGNAL

54.0 / 100

1 buyers · 3 purchase transaction lines · $5.0M gross purchase

WHY THIS SIGNAL?

Buyer breadthLow
Purchase sizeStrong
RoleModerate
RecencyLow
ConvictionStrong
Score anatomy

Each bar shows the contribution to the current score; the weights and formula stay unchanged.

Cluster+7.0 / 35
Purchase size+21.7 / 25
Role+13.0 / 20
Recency+2.9 / 10
Conviction+9.5 / 10

What is holding the score back?

  • ⚠ Cluster breadth is moderate · 1 insider(s), not 4+
  • ⚠ Role scores low · most senior buyer: President and CEO (CEO, chair and 10% owners score lowest)
  • ⚠ Purchase activity is becoming less recent

Purchase-size comments are relative to the model scale. Average daily volume is a separate market-context diagnostic.

US-v1.2 ranks qualifying equity purchases under the current 180-day rules. The score is a research priority, not a return forecast or probability. Backtests have not shown that a higher US score is followed by better returns.

Insider activity timeline

Owner lanes show the latest 180 days. Symbol shape identifies the transaction type; sales remain context only.

AprMayJunJulAugSepOct
Cann Cynthia CammettChief Accounting Officer
○○▼
Hill John WDirector
○▼
FLORANCE ANDREW CFounder and CEO
●●
SAINT FREDERICK G.President, Marketplaces
○
Sams Louise SDirector
○
Musslewhite Robert WDirector
○
● Purchase▼ Sale○ Other

Showing the six most active owners; 6 additional owner(s) remain in Form 4 evidence.

Purchase breadth & concentration

QUALIFYING BUYERS1
PURCHASE CONCENTRATION100%Largest buyer: FLORANCE ANDREW C · $5.0M
CLUSTER BUYING · 15D1 insiderPeak activity: 2026-05-01–2026-05-01

Roles in the peak window: President and CEO. Concentration uses priced qualifying P lines only and does not change the saved score.

SIGNAL HISTORY

54.0 / 100

Latest recorded score

↓ -0.2 ptsversus the previous recorded snapshot
  1. 54.3
  2. 54.3
  3. 54.2
  4. 54.2
  5. 54.0

Only scores saved when a full US scoring run completed are shown; gaps are not reconstructed.

Recent Form 4 activity

7Purchases
4Sales
43Other Form 4 lines
48SEC filings · 365 days
BUYING3 qualifying P line(s) · 180 days
SELLING2 sale line(s) · context only
OTHER12 exercise / withholding / award / gift / other lines
10b5-1 / PLANNEDNot detected in parsed evidence

P is an open-market or private purchase. S is a sale. M, F, A and G usually describe exercises, tax withholding, awards and gifts. These categories remain visually separate.

Market context

Market context provides additional background on recent price performance and risk. It does not affect the Insider Signal.

Price performance

1M
+0.6%
3M
+3.1%
6M
-18.7%
12M
-62.4%

Volatility & liquidity

Volatility
39.3%
Beta
—
Avg daily value
USD 206.2M

Valuation

Market cap
USD 12.0B
P/E
1849.6×

Fundamentals

Profit margin
0.2%
ROE
0.1%
Industry
Real Estate Services

Market data

Price data up to: 2026-10-11 · Price source: OpenBB/yfinance; volume from price cache (yfinance) · From SEC filings: Market cap, P/E, Profit margin, ROE · Fiscal year ended: 2025-12-31 · Market cap is the shares outstanding stated on the filing cover multiplied by the latest close. Share count date: 2026-07-27 · Status: PASS

Short interest

Short interest is external context reported to FINRA by broker-dealers. It does not affect the Insider Signal.

Shares short
13,284,736
Previous report
14,839,529
Avg daily volume
6,734,616
Days to cover
2.0

FINRA settlement date: 2026-09-30 · Captured 2026-10-12 · FINRA equity short interest ↗. A share count, published about a week after each of two settlement dates a month; not a percentage of shares outstanding.

Historical equity purchases

Qualifying code P transactions in the local Form 4 history, including purchases outside the current signal window.

Transaction dateReporting ownerTypeSecuritySharesAvg. priceApprox. valueSource
2026-08-04FLORANCE ANDREW CPurchase (P)Common Stock, par value $0.01 per share83,300USD 29.89USD 2,489,837SEC filing ↗
2026-05-01FLORANCE ANDREW CPurchase (P)Common Stock, par value $0.01 per share71,430USD 35.20USD 2,514,208SEC filing ↗
2026-03-06Sams Louise SPurchase (P)Common Stock, par value $0.01 per share1,000USD 48.36USD 48,360SEC filing ↗
2026-03-02SAINT FREDERICK G.Purchase (P)Common Stock, par value $0.01 per share20,000USD 45.33USD 906,600SEC filing ↗
2026-03-02Glaser Rachel CPurchase (P)Common Stock, par value $0.01 per share1,000USD 44.94USD 44,940SEC filing ↗
2026-02-27FLORANCE ANDREW CPurchase (P)Common Stock, par value $0.01 per share55,720USD 44.52USD 2,480,654SEC filing ↗
2024-10-25FLORANCE ANDREW CPurchase (P)Common Stock, par value $0.01 per share14,731USD 74.67USD 1,099,966SEC filing ↗

Form 4 evidence

54 transaction lines in the latest 365-day window; 392 in local history.

DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-10-15Rossmann Robin JackTax withholding (F)Common Stock, par value $0.01 per share756USD 32.00USD 24,192SEC filing ↗
2026-08-07Cann Cynthia CammettSale (S)Common Stock, par value $0.01 per share4,788USD 30.78USD 147,375SEC filing ↗
2026-08-05Hill John WSale (S)Common Stock, par value $0.01 per share3,500USD 30.21USD 105,735SEC filing ↗
Show recent Form 4 evidence (30 grouped rows)
DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-10-15Rossmann Robin JackTax withholding (F)Common Stock, par value $0.01 per share756USD 32.00USD 24,192SEC filing ↗
2026-08-07Cann Cynthia CammettSale (S)Common Stock, par value $0.01 per share4,788USD 30.78USD 147,375SEC filing ↗
2026-08-05Hill John WSale (S)Common Stock, par value $0.01 per share3,500USD 30.21USD 105,735SEC filing ↗
2026-08-04FLORANCE ANDREW CPurchase (P)Common Stock, par value $0.01 per share83,300USD 29.89USD 2,489,837SEC filing ↗
2026-08-01SAINT FREDERICK G.Tax withholding (F)Common Stock, par value $0.01 per share1,436USD 28.76USD 41,299SEC filing ↗
2026-08-01Cann Cynthia CammettTax withholding (F)Common Stock, par value $0.01 per share1,077USD 28.76USD 30,975SEC filing ↗
2026-07-01LOWN CHRISTIAN M.Tax withholding (F)Common Stock, par value $0.01 per share5,597USD 29.36USD 164,328SEC filing ↗
2026-06-23Sams Louise SAward / grant (A)Common Stock, par value $0.01 per share8,262USD 0.00USD 0SEC filing ↗
2026-06-23Musslewhite Robert WAward / grant (A)Common Stock, par value $0.01 per share8,262USD 0.00USD 0SEC filing ↗
2026-06-23McCarthy Christine MAward / grant (A)Common Stock, par value $0.01 per share8,262USD 0.00USD 0SEC filing ↗
2026-06-23Hill John WAward / grant (A)Common Stock, par value $0.01 per share8,262USD 0.00USD 0SEC filing ↗
2026-06-23Glaser Rachel CAward / grant (A)Common Stock, par value $0.01 per share8,262USD 0.00USD 0SEC filing ↗
2026-06-23Brunner Angelique G.Award / grant (A)Common Stock, par value $0.01 per share8,262USD 0.00USD 0SEC filing ↗
2026-06-23BERISFORD JOHN LAward / grant (A)Common Stock, par value $0.01 per share8,262USD 0.00USD 0SEC filing ↗
2026-06-15Cann Cynthia CammettTax withholding (F)Common Stock, par value $0.01 per share461USD 32.04USD 14,770SEC filing ↗
2026-05-01FLORANCE ANDREW CPurchase (P)Common Stock, par value $0.01 per share71,430USD 35.20USD 2,514,208SEC filing ↗
2026-03-15SIMURO FRANKTax withholding (F)Common Stock, par value $0.01 per share11,107USD 43.63USD 484,598SEC filing ↗
2026-03-15Ruggles LisaTax withholding (F)Common Stock, par value $0.01 per share2,977USD 43.63USD 129,887SEC filing ↗
2026-03-15DESMARAIS MICHAEL JTax withholding (F)Common Stock, par value $0.01 per share2,873USD 43.63USD 125,349SEC filing ↗
2026-03-15Cann Cynthia CammettTax withholding (F)Common Stock, par value $0.01 per share1,194USD 43.63USD 52,094SEC filing ↗
2026-03-15Boxer GeneTax withholding (F)Common Stock, par value $0.01 per share482USD 43.63USD 21,030SEC filing ↗
2026-03-15Boxer GeneTax withholding (F)Common Stock, par value $0.01 per share428USD 43.63USD 18,674SEC filing ↗
2026-03-10LOWN CHRISTIAN M.Award / grant (A)Common Stock, par value $0.01 per share12,268USD —USD —SEC filing ↗
2026-03-10FLORANCE ANDREW CAward / grant (A)Common Stock, par value $0.01 per share124,162USD —USD —SEC filing ↗
2026-03-10DESMARAIS MICHAEL JAward / grant (A)Common Stock, par value $0.01 per share17,676USD —USD —SEC filing ↗
2026-03-10Cann Cynthia CammettAward / grant (A)Common Stock, par value $0.01 per share4,374USD —USD —SEC filing ↗
2026-03-10Boxer GeneAward / grant (A)Common Stock, par value $0.01 per share21,920USD —USD —SEC filing ↗
2026-03-06Sams Louise SPurchase (P)Common Stock, par value $0.01 per share1,000USD 48.36USD 48,360SEC filing ↗
2026-03-02SAINT FREDERICK G.Purchase (P)Common Stock, par value $0.01 per share20,000USD 45.33USD 906,600SEC filing ↗
2026-03-02Glaser Rachel CPurchase (P)Common Stock, par value $0.01 per share1,000USD 44.94USD 44,940SEC filing ↗

Multiple price lines in one filing are grouped and share-weighted. Price and value are blank when a grouped filing line lacks price evidence.

Snapshot & identity

Snapshot date2026-10-18
Ranking versionUS-v1.2
Data qualityPASS ELIGIBLE · —
TickerCSGP
CIK0001057352
SectorReal Estate
IndustryReal Estate Services Yahoo Finance
SEC SIC7389 Services-Business Services, NEC
ExchangeNasdaq

Data coverage

Local Form 4 history392 transaction lines from 2020-01-11 to 2026-10-15
8 P purchase lines · 59 S sale lines · 325 other lines
SEC company submissionsOpen SEC filings ↗

Local ledger as of 2026-10-18. Mapping status is an audit field and does not erase SEC filing evidence.