Weitz Investment Management stated in its Q2 2026 investor letter that CoStar Group, Inc. (NASDAQ:CSGP) management remains undeterred in its residential real estate strategy after prevailing against an activist investor. While investors are skeptical of the plan, the firm believes the stock's current price reflects excessive punishment. CoStar shares closed at $31.56 on September 15, 2026, with a one-month return of -6.43% and a 52-week loss of 64.08%. The number of hedge fund portfolios holding CoStar decreased to 58 at the end of Q2, down from 62 in the prior quarter.