The Japanese yen jumped on Friday as investors sought protection against volatile stock moves, while the greenback dipped as stocks traded higher after a dramatic week capped by large price swings.
The benchmark S&P 500 tested its 20-month low early in the week and was at the brink of bear market territory before the three main indexes roared back with their biggest daily surge in nearly a decade on Wednesday and a late rally on Thursday.
The yen gained despite higher stocks, soft domestic data and a decline in benchmark Japanese bond yields, which fell back into negative territory for the first time in more than a year.
That suggests that there's still demand for some insurance against extended volatility over the holiday period that's keeping the yen better supported, said Shaun Osborne, chief FX strategist at Scotiabank in Toronto.
The Japanese currency was last up 0.62 percent against the greenback at 110.30 yen at 3:00 p.m. ET. Another safe-haven currency, the Swiss franc, also jumped 0.73 percent to 0.9803.
"Markets are a bit more cautious on risk appetite, with the Japanese yen and the Swiss franc gaining," said Lee Hardman, an FX strategist at MUFG in London.
The dollar index, a gauge of the greenback against a basket of six major currencies, fell 0.11 percent to 96.37.
The U.S. currency has been hurt in recent weeks by rising expectations that the Federal Reserve will pause its tightening cycle sooner than expected, or risk harming the U.S. economy with further interest rate increases.
A partial shutdown of the U.S. federal government, trade tensions between the United States and China and complications relating to Britains exit from the European Union are also keeping investors cautious.
"There's still a lot of potential risk and uncertainty out there," said Osborne.
Both chambers of the U.S. Congress convened for only a few minutes late on Thursday, but took no steps to end the partial federal government shutdown before adjourning until next week.