Tonight’s S&P quarterly rebalancing is a clean snapshot of where the market’s center of gravity has shifted. Lumentum (LITE) and Coherent (COHR) graduated to the S&P 500, leaving two vacancies in the S&P MidCap 400. The companies stepping into those slots tell you everything about the AI trade right now: Solstice Advanced Materials (SOLS) and ... Solstice Advanced Materials and SiTime Join the S&P MidCap 400 As AI Stocks Reshuffle the Index