CoStar's Stock Tumbles 4.37% as Legal Dispute Weighs Despite Earnings Beat Surges to 225th in Trading Volume Rankings

On August 12, 2025, CoStar Group (CSGP) closed at $88.46, down 4.37% with a trading volume of $450 million, a 96.45% increase from the previous day’s volume. The stock ranked 225th in trading activity for the session.

Recent developments highlight legal and operational challenges for CoStar. The company is embroiled in a high-stakes copyright infringement lawsuit against Zillow, alleging "rampant" use of CoStar’s watermarked photos. This case, if unresolved, could expose Zillow to over $1 billion in damages. Meanwhile, CoStar’s Q2 2025 earnings exceeded expectations, with revenue growth accelerating to 15% year-over-year, driven by robust net new bookings and expanded product offerings. Analysts noted strategic investments in sales and multifamily analytics, including the appointment of Grant Montgomery to lead national multifamily analytics.

Despite the earnings beat, the stock’s sharp decline reflects investor concerns over the legal dispute and broader market volatility. The lawsuit underscores risks tied to intellectual property in the real estate tech sector, while recent leadership changes and operational momentum remain key factors to monitor.

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