(Bloomberg) -- The S&P 500 Index is poised to end 2025 up more than 17% as the bull market continues for a third year driven by enthusiasm for artificial intelligence. The AI trade broadened out this year, as chip stocks again led the S&P 500 but were joined by the shares of companies tied to building the data centers that will power the technology. Three of the index’s top 10 performers in 2025 were data storage companies, which are among the main beneficiaries of the hundreds of billions of dollars in p ...