Vistra Set to Join S&P 500; Aaon to Join S&P MidCap 400; Marathon Digital Holdings to Join S&P SmallCap 600

NEW YORK, May 3, 2024 /PRNewswire/ — S&P MidCap 400 constituent Vistra Corp. (NYSE: VST) will replace Pioneer Natural Resources Co. (NYSE: PXD) in the S&P 500, S&P SmallCap 600 constituent Aaon Inc. (NASD: AAON) will replace Vistra in the S&P MidCap 400, and Marathon Digital Holdings Inc….