A Walmart executive recently laid out his company’s strategy for the holiday shopping season as follows: “We’re going to win”. Other retailers say the same. Heavy discounting is predicted, and victories may prove pyrrhic in profit terms. The stock market, however, has predicted one winner: Amazon.

Its shares, which had traded in line with consumer discretionary stock indices for three years, started to rally after the third-quarter report in October. Its market value has since risen by a quarter.

What has changed? Maybe nothing. There is a general fever for growth companies, especially those with a technological frisson. Netflix and Facebook shares have rallied, too. There was genuine improvement in Amazon’s third-quarter numbers – specifically, incremental sales in the quarter ($3.3bn) were greater than in the third quarter a year ago ($2.9bn). This is a big deal, as there had been incremental sales declines in the previous five quarters.