Lumentum Holdings, the photonics and optical know-how firm buying and selling beneath the ticker LITE, is being added to the Nasdaq-100 Index efficient Could 18, 2026. It replaces CoStar Group (CSGP) within the index that tracks the 100 largest non-financial firms listed on the Nasdaq change.
The inclusion caps one of many extra outstanding progress tales within the semiconductor-adjacent area. LITE shares have surged between 145% and 150% year-to-date in 2026, constructing on a 339% acquire in 2025. The corporate’s market capitalization now sits at roughly $70 billion, dwarfing CoStar Group’s $13 billion valuation and making the swap look nearly inevitable.
From area of interest optics to index heavyweight
The corporate makes a speciality of photonic and optical applied sciences, the parts that assist knowledge journey on the pace fashionable AI workloads demand. As hyperscale cloud suppliers have raced to construct out the high-bandwidth networks wanted to coach and deploy giant language fashions, Lumentum has discovered itself sitting on precisely the proper product portfolio at precisely the proper time.
Nasdaq introduced the index change on Could 8, 2026, and LITE shares ticked up 1.2% intraday on the information.
The highway to the Nasdaq-100
This isn’t Lumentum’s first main index milestone in latest months. The corporate was added to the S&P 500 on March 23, 2026, a transfer that itself mirrored simply how rapidly the corporate’s valuation and buying and selling profile had expanded.
The Nasdaq-100 is a market-cap-weighted index, that means bigger firms carry extra affect on its efficiency. At $70 billion, Lumentum received’t be one of many heaviest weights within the index, the place Apple, Microsoft, and Nvidia command multi-trillion-dollar valuations.
CoStar Group, the business actual property knowledge agency being eliminated, tells the opposite facet of that story. At $13 billion in market cap, it now not ranks among the many 100 largest non-financial Nasdaq names.
What this implies for traders
Index inclusion issues for causes that transcend status. When a inventory joins the Nasdaq-100, each ETF and index fund monitoring that benchmark has to purchase shares. The Invesco QQQ Belief manages lots of of billions in property, and compelled shopping for from passive automobiles creates structural demand for the inventory.
For passive traders who maintain broad market index funds, Lumentum’s inclusion means they now have publicity to the corporate whether or not they sought it out or not.
