The latest yen depreciation underscores just how oversold the currency is, says Stefan Angrick at Moody's Analytics. Rate spreads between Japan and the rest of the world have narrowed, oil prices have cooled and Japan's fiscal position is in its best shape in decades. "There is simply no reason for the yen to be as weak as it is, which keeps the possibility of intervention firmly on the table." If Japan does intervene, the impact of a coordinated move involving the U.S. and other Asian central banks would likely be far more durable. A joint effort would, at the very least, establish a more meaningful floor under the yen, Angrick reckons. It could also help reverse some of the extreme currency weakness seen across Asia, something Washington likely isn't too comfortable with. (fabiana.negrinochoa@wsj.com)