The U.S. joined Japan in buying yen, helping reverse the currency's slide as authorities signaled that further coordinated action remained possible.

July 31 : The U.S. Treasury intervened to support the yen on Friday through outright purchases, the Financial Times reported, joining Japan in its efforts to boost the currency…

Coordination between Japan and the United States now appears to be the tightest in decades, fuelling one of the most notable rebounds since the yen began its years-long slide.