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CSGP +6.6%: an unusually large move for this stock. COSTAR GROUP, INC. moved 5.7 points more than its sector, on 0.6× its usual volume.

2026-10-15 · CSGP

CSGP +6.6%: an unusually large move for this stock

COSTAR GROUP, INC. moved 5.7 points more than its sector, on 0.6× its usual volume.

The story in plain words

Thursday, October 15, 2026. CSGP +6.6%: an unusually large move for this stock. COSTAR GROUP, INC. moved 5.7 points more than its sector, on 0.6× its usual volume.

What the data shows for CoStar Group (CSGP): CSGP +6.6% today. Its sector fund (XLRE) +0.9% today. S&P 500 (SPY) +0.4% today.

Worked out from that data: 5.7 points more than its sector. Volume 0.6× its 20-day average. Bigger than 96% of its daily moves over the past 250 trading days. After the 10 most similar CSGP days since Oct 27, 2021, the stock was higher 5 days later 7 of 10 times (History, not a forecast).

Possible contributors. These line up in time with the move; they are not confirmed causes: News: “Discover which S&P500 stocks are making waves on Thursday.” (Published around the move. Timing only, not a confirmed cause). News: “BR Stock Rises 14.3% in Three Months: Here's What You Should Know” (Published around the move. Timing only, not a confirmed cause).

About the company: CoStar Group trades as CSGP and is part of the S&P 500, in the Real Estate sector (Real Estate Services), headquartered in Washington, D.C., founded in 1987.

This is one of CookieStocks’ daily stock stories about unusually large one-day price moves in S&P 500 stocks, measured against each stock’s own history, its sector and its usual volume. Stories are found automatically each trading day from market data and SEC filings, and every claim is labelled as observed, calculated or a possible contributor. Statistics only, not investment advice.

Prove it

Every claim on the graphic, labelled: observed (straight from the data), calculated (worked out from it), or possible contributor (lines up in time, not a confirmed cause).

  • OBSERVED
    CSGP +6.6% todayOct 15, 2026, 3:35 PM ET
  • OBSERVED
    Its sector fund (XLRE) +0.9% todayOct 15, 2026, 3:35 PM ET
  • CALCULATED
    5.7 points more than its sectorHow: stock return − sector fund return · Oct 15, 2026, 3:35 PM ET
  • OBSERVED
    S&P 500 (SPY) +0.4% todayOct 15, 2026, 3:35 PM ET
  • CALCULATED
    Volume 0.6× its 20-day averageHow: today’s volume ÷ average of the last 20 days · Oct 15, 2026, 3:35 PM ET
  • CALCULATED
    Bigger than 96% of its daily moves over the past 250 trading daysHow: share of past daily moves smaller in size · Oct 15, 2026, 3:35 PM ET
  • POSSIBLE CONTRIBUTOR
    News: “Discover which S&P500 stocks are making waves on Thursday.”Published around the move. Timing only, not a confirmed cause. · Oct 15, 2026, 12:35 PM ET
  • POSSIBLE CONTRIBUTOR
    News: “BR Stock Rises 14.3% in Three Months: Here's What You Should Know”Published around the move. Timing only, not a confirmed cause. · Oct 14, 2026, 10:38 AM ET
  • CALCULATED
    After the 10 most similar CSGP days since Oct 27, 2021, the stock was higher 5 days later 7 of 10 timesHistory, not a forecast. · How: same-company days with a move of similar size and direction

CoStar Group (CSGP) financials and filings →

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Statistics only, not investment advice. Past moves don’t predict future ones. Data as of Oct 15, 2026, 3:35 PM ET.