Nuclear power companies Constellation Energy and Vistra have become the top S&P 500 performers after Super Micro and Nvidia, as investors look beyond semiconductors and bet on firms catering to an artificial intelligence boom in any capacity. Shares of Vistra have jumped 132% this year, and those of Constellation Energy climbed 81%, compared with a 16.7% rise in the benchmark S&P 500, as rising demand for power from data centers, manufacturers and electric vehicle makers creates a need for clean and sustainable supply of energy. More than 20% of large cap funds own at least Vistra or Constellation’s stock compared to just 13% at the beginning of the year, BofA said.