Gold's surge to a fresh record high is being fuelled by fears of an escalating global trade war instigated by U.S. President Donald Trump.

Up 44% over the last year, gold has been by far the best-performer across a basket of 12 leading global asset classes over the period, according to the BlackRock Investment Institute, most notably trouncing the 22% return for the S&P 500 over the last year, including reinvested dividends.

Gold hit a record — rallying closer toward a test of $3,000 an ounce — after President Donald Trump imposed tariffs on US steel and aluminum imports, adding to uncertainty in global markets and stoking haven demand.