Investors have favored havens this year as the coronavirus pandemic rips through economies. That's spurred sustained inflows into gold-backed exchange-traded funds as central banks and governments unleash vast stimulus programs.

"A massive investor response to Covid-19 has pushed ETF holdings to record levels, the impact of which has outweighed the decline in jewelry demand and absorbed increases in recycling," James Steel, chief precious metals analyst at HSBC Securities (USA) Inc., said in a note. Further inflows are expected "as investors respond to elevated risks and low yields."

Holdings in gold-backed ETFs increased to 3,234.6 tons on Tuesday, according to initial data compiled by Bloomberg. That's up 655.6 tons so far in 2020, topping the tonnage increase seen in 2009. The total has climbed every month this year.

Gold extended gains Wednesday amid worries over the pandemic, new tensions between the U.S. and China, and a weakening U.S. dollar.