We have shown versions of this chart before, but given the recent price action it is worthwhile to revisit. This Great Graphic, constructed on Bloomberg, shows the dollar against the yen in white and the Nikkei in yellow. It shows them moving in lockstep.
Most recently the dollar-yen has been lagging a day or two behind the Nikkei. Despite the pre-weekend gains, it is not clear that the Nikkei has bottomed and some of the slide in dollar into the weekend, seems to have been spurred by the erosion of U.S. shares and the decline in the Nikkei futures.
The Nikkei has neared a 50% retracement of the gains seen since the Japanese election was announced in mid-Nov last year. The dollar has surrendered about 40% of its gains. The 50% retracement comes in near JPY91.50. This is a rather simplistic projection, but the point is the given current relationships, one cannot be sure the dollar bottoms against the yen until the Nikkei bottoms.