On the 26th, the won-dollar exchange rate closed at 1,440.6 won per $1, down 25.2 won from the previous transaction day. The move came as U.S. and Japanese foreign exchange authorities showed signs of intervening in the market to curb the weak yen. The won tends to move in tandem with the yen; typically, when the yen strengthens, the won also rises in value (the won-dollar exchange rate falls).
That day, the won-dollar exchange rate opened at 1,446.1 won, down 19.7 won from the previous transaction day. The yen, which was in the upper 159s per $1 on the 23rd, the previous transaction day, slumped into the 155s. The yen fell after reports that the Bank of Japan conducted a "rate check," a procedure in which it asks major banks about transaction conditions before intervening in the foreign exchange market. In addition, outlets including the Financial Times reported that the Federal Reserve Bank of New York also conducted a rate check at the direction of the U.S. Treasury, fueling a rise in the yen (a fall in the dollar-yen exchange rate). As a result, on the 23rd the yen posted its biggest decline in six months.
With this, the won-dollar exchange rate finished lower for a fourth straight day. President Lee Jae-myung said on the 21st that "according to the responsible authorities, in about a month or two it will fall to around 1,400 won," and it has been trending down since. During this period, the won-dollar exchange rate fell from 1,478.1 won to 1,440.6 won.
Park Sang-hyun, a researcher at iM Securities, said, "Whether the yen's additional strength continues after U.S.-Japan coordination on foreign exchange policy is the biggest issue in the (FX market)," adding, "If the yen strengthens further, bearish sentiment on the dollar will spread."