CoStar's Stock Slides 0.88% as $230M Volume Ranks 429th Amid Institutional Buys and Insider Sells

CoStar Group (NASDAQ: CSGP) closed August 8, 2025, with a 0.88% decline, trading at $94.60 per share. The stock recorded a daily trading volume of $230 million, ranking 429th in market activity. Institutional ownership saw notable changes, with Weitz Investment Management Inc. increasing its stake by 2.4% to 911,600 shares, representing 0.22% of CoStar’s market capitalization. Additional institutional investors, including Cullen Frost Bankers Inc. and Pin Oak Investment Advisors Inc., added new or expanded positions in the first quarter, with cumulative holdings valued at $29,000 to $41,000. Over 96% of CoStar’s shares remain under institutional control.

Insider activity also influenced market sentiment. Frederick G. Saint, a CoStar executive, sold 25,000 shares for $2.33 million, reducing his ownership by 7.26%, while CFO Cynthia Cammett Cann sold 2,033 shares for $188,764, trimming her stake by 7.31%. These sales, disclosed via SEC filings, highlight shifting internal ownership dynamics. Meanwhile, Homes.com, a CoStar subsidiary, released a July housing market report showing moderate price growth and increased inventory levels, potentially signaling evolving demand trends in the residential real estate sector.

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