S&P 500, MidCap 400, and SmallCap 600 Welcome New Members as Indexes Rebalance for 2026

Group 1 - The S&P Dow Jones Indices announced changes to the S&P 500, S&P MidCap 400, and S&P SmallCap 600 indexes, effective December 22, 2025, with new members including Carvana, Comfort Systems USA, and CRH [1] - The S&P 500 and other indexes rebalance regularly to reflect market performance, allowing companies to move between indexes based on their market capitalization and stock price performance [2][4] - Carvana serves as an example of a company that has successfully transitioned from a penny stock facing bankruptcy to being included in the S&P 500 after improving its financials and achieving significant growth [3] Group 2 - Companies must meet specific criteria to be included in the S&P 500, including sufficient market capitalization, adequate trading volume, a majority of shares in public hands, at least one year since their IPO, and consecutive positive earnings [5] - Companies are removed from the index when they consistently fail to meet performance criteria, although there are no strict rules governing this process [6] - A historical example is United States Steel, which was removed from the S&P 500 in 2013 after its market cap fell below $4 billion, demonstrating the dynamic nature of index membership [7]