Updates with stock milestone, additional context

** Optical-technology maker Lumentum's LITE.O shares up 15% at $1,039.22 and hit fresh record on Mon as it's set to join the Nasdaq-100 index .NDX next week

** LITE's stock surpasses previous intraday all-time high of $1,021 achieved on May 5

** LITE to replace real-estate analytics firm CoStar CSGP.O in the NDX effective Mon, May 18, Nasdaq Global Indexes announced late Fri

** CSGP stock down fractionally on the session

** NDX comprises 100 of the largest Nasdaq-listed non-financial companies and is tracked by more than 200 investment vehicles with combined $600 bln in assets under management, according to Nasdaq's release

** LITE, which joined the S&P 500 .SPX in Mar, had roughly $70 bln market cap as of Fri

** Stock now up 183% YTD and is 5th best performer among current SPX components

** LITE last week forecast qtrly rev above Wall Street's expectations, betting on strong demand for its high-speed optical components that are crucial for AI infrastructure

** Co and its rival Coherent COHR.N in Mar each received a $2 bln investment from AI industry leader Nvidia NVDA.O

** 20 of 25 analysts rate LITE stock "strong buy" or "buy", 5 "hold"; median PT $1,100, per LSEG data

** Meanwhile, NDX up 16% in 2026, twice the SPX's advance