Group 1 - Robinhood Markets' shares have risen by 13.5% following the announcement of its inclusion in the S&P 500 index, while the S&P 500 and Nasdaq Composite have gained 0.1% and 0.5% respectively [1] - The company will officially join the S&P 500 index on September 22, replacing Caesars Entertainment, which typically leads to increased demand for the stock as fund managers adjust their portfolios [2][7] - Robinhood's inclusion in the S&P 500 validates the company in the eyes of investors and is expected to attract more institutional interest, especially as it continues to innovate and expand its product offerings [3] Group 2 - The CEO of Robinhood, Vladimir Tenev, previously expressed uncertainty about the timing of the company's inclusion in the S&P 500 during a shareholder meeting, indicating it was a challenging goal to plan for [3] - Despite the stock carrying a significant premium, there is optimism regarding the company's future success [4]