Interactive Brokers Group Inc. (ticker: IBKR) will join the S&P 500 Index effective August 28, 2025, replacing Walgreens Boots Alliance Inc. (ticker: WBA). The announcement by S&P Dow Jones Indices has led to a notable increase in Interactive Brokers' share price, with gains of up to 8% in postmarket trading and approximately 6% after hours. This inclusion reflects Interactive Brokers' growing prominence in the retail trading and fintech sectors. Concurrently, Talen Energy Inc. (ticker: TLN) is set to join the S&P MidCap 400, replacing Interactive Brokers in that index. The move has drawn attention as other fintech companies such as Robinhood and AppLovin were not included in this rebalancing. Interactive Brokers' founder, Thomas Petterffy, has also been highlighted in discussions surrounding the index change. The inclusion will take effect prior to the market open on August 28, 2025.