KKR (NYSE:KKR) stock is up on Monday as investors prepare for the company to be added to the S&P 500 later this month.The S&P 500 is set to undergo its quarterly rebalance on June 21. When that happens, several stocks will be replaced on the index by new stocks. This will see them join the index before markets open on June 24.KKR won’t be alone when it joins the S&P 500. It will do so alongside GoDaddy (NYSE:GDDY) and CrowdStrike (NASDAQ:CRWD) shares. This will see them replace Robert Half (NYSE:RHI), Comer ...