Lumentum Holdings, a photonics and optical technology company trading under the ticker LITE, will be added to the Nasdaq 100 Index on May 18, 2026. It replaces Coster Group (CSGP) in an index that tracks the 100 largest non-financial companies listed on the NASDAQ exchange.
This inclusion caps one of the most remarkable growth stories in the semiconductor-adjacent space. LITE stock has increased 145% to 150% year-to-date in 2026 and 339% in 2025. The company’s market capitalization now stands at about $70 billion, well below CoStar Group’s $13 billion valuation, making an acquisition seem all but inevitable.
From niche optics to index heavyweights
The company specializes in photonic and optical technologies, components that help transfer data at the speeds modern AI workloads demand. As hyperscale cloud providers race to build the high-bandwidth networks needed to train and deploy language models at scale, Lumentum finds itself in exactly the right product portfolio at just the right time.
Nasdaq announced the index changes on May 8, 2026, and LITE stock rose 1.2% intraday on the news.
Road to Nasdaq 100
This isn’t Lumentum’s first major index milestone in recent months. The company was added to the S&P 500 on March 23, 2026, a move that itself reflected how quickly the company’s valuation and trading profile had expanded.
The Nasdaq-100 is a market-capitalization weighted index, meaning larger companies have more influence on their performance. At $70 billion, Lumentum won’t be one of the most heavily weighted companies in the index while Apple, Microsoft, and Nvidia boast multitrillion-dollar valuations.
Excluded commercial real estate data company CoStar Group told the other side of the story. With a market capitalization of $13 billion, it is no longer ranked among the top 100 non-financial stocks on the Nasdaq.
What this means for investors
Index inclusion is important for reasons beyond prestige. When a stock joins the Nasdaq 100, all ETFs and index funds that track that benchmark must buy the stock. Invesco QQQ Trust manages hundreds of billions of dollars in assets, and forced purchases from passive vehicles are creating structural demand for shares.
For passive investors who hold broad market index funds, Lumentum’s inclusion means they have exposure to the company whether they asked for it or not.
