TOKYO -- The Japanese yen briefly hit a nine-month high against the U.S. dollar on Jan. 3, soaring as much as 4 yen, or 3.9%, in just one minute as hedge funds and other overseas investors took advantage of thin liquidity during the New Year's holiday here.
The yen's sharp rally, or a "flash crash" in the dollar and other currencies, was driven by massive buying of the yen as a sharp rise in the Japanese currency triggered stop-loss orders from retail investors in Japan and then artificial intelligence-based trading systems worldwide.
