S&P DJI Keeps Core Rules, Adds Thresholds for MegaCap Additions

S&P Dow Jones Indices completed a market consultation on MegaCap treatment and will maintain the current eligibility criteria for the S&P 500, S&P MidCap 400, and S&P SmallCap 600 (financial viability, seasoning, and IWF) while not granting exceptions based solely on market cap. For the broader S&P Total Market Index, S&P Completion Index, and Dow Jones U.S. Total Stock Market Index, new entry criteria are proposed: a stock must have either an IWF of at least 0.10 or a float-adjusted market cap at least 10% of the 100th largest company in the respective index. Current constituents still have no minimum, and exceptions to the viability, seasoning, and IWF rules remain unlikely to be granted purely on market cap. The Float release after IPO lock-ups may be phased, and IPOs meeting the updated IWF rules could fast-track into the indices. Implementation is set to take effect before market open on June 8, 2026.