THE market gyrations around Donald Trump's accession to the presidency are a twist on the old stock-market adage about buying on rumours and selling on news. The Dow Jones Industrial Average had one of the strongest post-election rallies in history up until a couple of weeks ago, rising by more than 12 per cent to the cusp of the 20,000 level as traders speculated wildly about the likely economic policies that the pro-business president elect would enact. But hopes that Mr Trump would hit the ground running with a clear economic agenda have faded as the first 100 days promise to be as haphazard and improvised as his campaign.

The softness looks set to continue this week as Mr Trump's agenda remains in a state of flux.

Through Thursday, the Dow Jones Industrial Average had fallen for five straight sessions and even turned negative on 2017. Optimism returned to the fore on Mr Trump's inauguration on Friday and major indexes crept back up towards record highs, but there remained a sense that the new administration could produce as many nasty surprises for investors as pleasant ones.