US stock-market indexes were switching between small gains and losses on Friday, a day after equities plunged on the prospect of a global trade war as China fired its first retaliatory salvo against tariffs on at least $50bn of Chinese goods announced by the Trump administration, MarketWatch reports.

Investors sought shelter in gold and the Japanese yen, which was trading at its highest levels since the US presidential election in 2016, after one of the worst days for Wall Street in weeks.