Robinhood and Strategy fail to be included in S&P 500, sending their shares down

Shares of trading platform Robinhood Markets and Bitcoin holding company Strategy declined in after-hours trading amid Monday's broader market decline after being excluded from the S&P 500. S&P Dow Jones Indices announced Monday evening that Interactive Brokers Group will join the index of the 500 largest U.S. companies at market open Thursday, replacing drugstore chain Walgreens Boots Alliance.