Six artificial intelligence-linked companies have driven more than half of the S&P 500's gains since April, leaving the US stock market more dependent on a single cluster of technology firms than at any time since the dot-com era, according to an ABC News analysis. Experts quoted in the report warn the concentration, and the web of companies financing each other's AI spending, is creating new risks for the wider economy.
organisation
S&P 500
US stock market index of 500 large companies