S&P Dow Jones Indices said Monday it will add Interactive Brokers Group to the S&P 500, effective before the opening of trading on Aug. 28. The online brokerage will enter the benchmark’s financials sector, replacing Walgreens Boots Alliance. Walgreens is being removed as it prepares to be acquired by private-equity firm Sycamore Partners. A Nasdaq notice states the drugstore chain’s shares will be halted after the close of trading on Wednesday, which will be its last day on the exchange ahead of delisting. In after-hours trading following the announcement, Interactive Brokers’ stock rose more than $2 as index-tracking funds positioned for the rebalancing.