It painted the sharp drops in the values of Twitter, Facebook and other internet companies in recent weeks as a hiccup, one that is likely to be corrected in the next few months. According to Goldman Sachs, the earnings and valuations of technology companies as a proportion of the S&P 500 index are now equal, whereas the peak of the dotcom boom saw earnings accounting for 14pc of the S&P and values making up a third of its total market capitalisation.