Donald Trump last night declared ‘America is back’ after stocks on Wall Street soared to a record high. The flagship S&P 500 index – stuffed full of US corporate titans from Nvidia and Apple to Goldman Sachs and Boeing – passed 7,000 for the first time. ‘The S&P 500 just hit 7,000 for the first time ever. The turmoil saw investment giant St James’s Place yesterday deliver a £440m boost to UK stocks amid concerns that the artificial intelligence (AI) bubble in the US could burst, causing ‘carnage’. A mania for America’s huge tech firms has helped divert investor cash across the Atlantic to Wall Street in recent years.