The US has helped pull Japan’s yen out of a 40-year low. Why?

Only days ago, the Japanese yen’s descent showed no signs of stopping, having already dropped to a 40-year low. But by Monday morning – after a rare intervention on the currency’s behalf by Tokyo and Washington – it surged as high as 155.23 per US dollar, its strongest level since early May, according to Chinese financial data provider Wind. The joint action took on an extra layer of intrigue afte