Americans can at least be thankful for their Thanksgiving rally. Last week saw the best week for US stocks in 75 years, with the S&P 500 gaining 12.5 per cent. This set up a test: as Bespoke Investment pointed out, the S&P closed last week just above a sharply downward trend line formed by its closing prices since the acute phase of the crisis began with September’s collapse of Lehman Brothers.

If stocks could close up for a sixth successive day, they might truly have broken that trend. Instead a sell-off wiped out most of last week’s gains, with the S&P falling almost 9 per cent.