** Trading platform Interactive Brokers' IBKR.O shares rise 4.5% to $65.59 in extended trading
** IBKR will replace Walgreens Boots Alliance WBA.O in the benchmark S&P 500 index .SPX, effective prior to opening of trading on August 28
** Walgreens is set to be taken private by buyout firm Sycamore Partners, with the deal expected to close later this week
** Meanwhile, power producer and energy infrastructure company Talen Energy TLN.O will replace IBKR in the S&P MidCap 400 index, effective prior to opening of trading on August 28
** Talen Energy's shares up 4.6% at $372
** Also, midstream operator Kinetik KNTK.N will join the S&P SmallCap 600 index, effective prior to opening of trading on September 2
** Kinetik's shares up 5.9% at $43.03