In the United States, Marvell Technology and Flex are set to join the S&P 500 index on June 22, 2026, replacing Pool Corp. and The Campbell’s Company. This decision comes after Marvell reported a quarterly forecast that surpassed estimates, driven by increased demand for chips used in artificial intelligence data centers. The semiconductor company is experiencing a surge in demand for computer systems that support AI software and services, which has positively impacted its stock performance. Flex, on the other hand, has provided profit guidance for 2027 that also exceeded market expectations and announced plans to spin off its cloud and power infrastructure segment. The S&P 500 index has specific eligibility requirements, including a minimum market capitalization of $22.7 billion, along with profitability, liquidity, and share-float criteria. These guidelines were established in April and are crucial for companies seeking inclusion in the index. The growth of passive investing has made it increasingly important for companies to be part of this benchmark, as index funds must buy shares of newly added companies. Conversely, removal from the index can negatively impact a stock's performance due to the selling of shares by index funds to realign with the new composition. The index provider, SPDJI, recently reaffirmed its existing eligibility requirements, which means that companies like SpaceX will not gain immediate access to the S&P 500 despite their significant market sizes. This decision reflects a broader trend in Wall Street, where some companies are achieving unprecedented valuations before entering public markets. The lack of expedited entry for large tech IPOs has implications for companies looking to tap into the trillions of dollars that are benchmarked to the S&P 500. As Marvell and Flex prepare for their inclusion in the S&P 500, their respective stock prices have already shown positive movement, with Marvell's shares rising by 6% in after-hours trading and Flex's shares increasing by 2%. This upward trend indicates investor confidence in both companies as they transition into this prestigious index, which is often seen as a mark of stability and growth in the financial markets.