Electric and power generation firm Vistra will join the S&P 500 index before Wednesday's open, S&P Dow Jones Indices said Friday night. VST stock will replace Pioneer Natural Resources, which is being acquired by Exxon Mobil.
Meanwhile, bitcoin miner Marathon Digital will be added to the S&P SmallCap 600. Heating and AC play AAON will move up to the S&P MidCap 400 index, replacing Vistra.
Vistra stock rose 2.15% to 83.24, hitting fresh all-time highs. Shares have skyrocketed 116% so far in 2024, as data centers' power needs have soared with the AI boom. Vistra reports Q1 earnings on Wednesday morning.
Marathon Digital stock skyrocketed 18% to 20.68 back above its 50-day line. MARA stock earnings are due late Thursday.
Meanwhile, AAON is getting a promotion, but fewer funds track the S&P MidCap 400 than the S&P SmallCap 600. AAON stock fell 2.8% to 76.20. Shares of the heating and A/C specialist plunged 13.7% on Friday following earnings.