The yen swung sharply from the day’s low to near its high amid jittery trading in the wake of the Bank of Japan’s decision to keep monetary policy unchanged.

It traded down 0.6% at ¥156.51 as of 5:41 p.m. in Tokyo after earlier being at the day’s weak point of ¥156.82. Gov. Kazuo Ueda indicated that monetary policy will stay easy for now, with the currency touching a fresh 34-year low versus the dollar Friday.

The yen’s extended slump has heightened speculation that authorities may intervene in the market as soon as Friday, with further risks to come later when data on the U.S. Federal Reserve’s preferred inflation gauge is released.