Reddit Stock Jumps On S&P 500 News

Reddit stock jumped late Thursday on news that the social media firm will join the S&P 500 index. Sun Communities will be added to the S&P MidCap 400. Reddit will be added to the S&P 500 index before the open on Tuesday, Aug. 18. It'll replace AvalonBay Communities (AVB), which is being acquired by S&P 500 member Equity Residential (EQR).…