CoStar Group (CSGP) exited the Nasdaq-100 Index before the market opened on May 18, 2026. Lumentum Holdings Inc. (LITE) replaced the real estate information firm in the benchmark.
CoStar’s market value declined nearly 57% over the past year. Investors cited concerns regarding the company's strategy and capital allocation as primary drivers for the removal.
The exclusion triggers mandatory selling by funds mirroring the Nasdaq-100. This index serves as a benchmark for over $600 billion in assets under management. The transition is expected to increase trading volume and create temporary downward pressure on CSGP shares.