Gold, silver and platinum rallied to one-month highs on Tuesday as concerns over the outcome of the U.S. election sparked losses in stocks and the dollar, prompting investors to seek out precious metals as a haven from risk.
The announcement of an FBI investigation into Hillary Clinton's use of a private email server during her time as Secretary of State helped send the so-called "fear index" of market volatility to its highest in a month on Tuesday, fueling risk aversion.
Opinion polls show Democrat Clinton's lead over Republican Donald Trump has narrowed slightly since early last week.
"The Trump risk seems to be back in the market at least to some extent," Commerzbank analyst Carsten Fritsch said. "One common factor is certainly the weaker dollar today." A Trump win would likely boost gold due to uncertainty over U.S. economic and foreign policy, HSBC said in a note, citing also a protectionist slant to Trump's policies and his commitment to tax cuts, which are expected to increase the federal deficit.