CoStar Shares Drop 1.1% as Legal Dispute with Zillow Looms, Stock Traded 484th in $0.3B Volume

On July 31, 2025, CoStar Group (NASDAQ: CSGP) closed with a 1.10% decline, trading at a volume of $0.30 billion, ranking 484th in daily trading activity. The stock’s performance followed a mixed mix of corporate developments and market dynamics.

The company announced a significant legal action against Zillow, alleging widespread copyright infringement involving tens of thousands of its watermarked photographs. The lawsuit, filed in a New York federal court, accuses Zillow of unlawfully exploiting CoStar’s content across platforms like Redfin and Realtor.com. The case could have long-term implications for CoStar’s intellectual property strategy and market positioning.

CoStar’s Q2 2025 financial results highlighted robust operational momentum. Revenue surged 15.3% year-on-year to $781.3 million, driven by growth in core platforms such as Apartments.com, Homes.com, and LoopNet. Non-GAAP earnings per share reached $0.17, surpassing analyst expectations by 23.4%. The firm also reported record quarterly net new bookings of $93 million and a 56% increase in Homes.com memberships compared to Q1 2025.

Strategic leadership changes further underscored CoStar’s focus on expansion. Grant Montgomery was appointed as National Director of Multifamily Analytics, enhancing the company’s analytical capabilities in the U.S. multifamily sector. Meanwhile, Alexa-Maria Rathbone Barker’s promotion to Head of CoStar Europe signals a renewed emphasis on international market development.

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