For now, even a threat of tariff escalation may be discounted by a feeling that ‘Trump always chickens out’

The final classic of England’s horse racing season is the St Leger’s Day race at Doncaster, on September 13 – made famous by the stockbroker’s mantra, “Sell in May and go away, come again St Leger’s Day”. This referred to well-heeled brokers taking long summer holidays when trading was subdued and left in the hands of junior dealers.

Mantras like these recognise that markets show a definite seasonality, with quiet summers giving way to an often-exciting October as money movers return to work. These indicators can be combined with more traditional forecasts of the near-term future, made by looking at the near-term past and assisted by our experiences.

In some ways, Trump’s extreme negotiating technique sounds smart in making us think 30 per cent is good – when it still essentially hurts all but the highest added-value trade.

China, US slash most tariffs on each other after first round of trade talks