Marvell Joined the S&P 500 on Monday. Then the Stock Fell. Here Is Why That Is Normal.
Marvell Technology officially entered the S&P 500 on June 22 after being up 260% in 2026. The stock fell nearly 4% on its first day in the index. The pattern has a name: sell the news. Here is how it works and what it means for the AI trade.





