Mr McDonald, who runs the multi-manager fund with Marcus Brookes, said the fund now had a 15 per cent exposure to the US - including a 1.5 per cent weighting to an exchange traded fund that represents a long dollar and short euro position.
He said: "When everything else is doing badly the things which do well are US Treasuries and the dollar.
"If you don't like government bonds because they offer poor value, the dollar is the main thing you are left with to express an anti-risk view."
Mr McDonald said the dollar was attractive at present because many rival investors were shorting the currency, meaning his long position carried a compelling valuation.
He added: "If the dollar goes up by 10 per cent that could make the fund 30-35 basis points, which is helpful in this environment."
Mr McDonald said the euro/dollar trade had been range trading since he took it on, having increased by 20 per cent and then giving up these returns, but he would consider topping the position up if the trade fell in value.
Elsewhere in the fund, the manager has added roughly a 2 per cent position in Paul Thursby and Peter Geikie-Cobb's £1bn Thames River Global Bond fund, which he said was a "diversified" offering.
The Cazenove Diversity fund has returned a second quartile 12.8 per cent over three years to May 27,
