The Nikkei 225 opened down 1% but has quickly pared that to 0.8%.
The chart shows a head-and-shoulders pattern that resolved with the fall to 25,600. We got a bounce from there up to the old neckline but we're now getting a double top there. On a break of 26,600, I'd expect to see a fall down to the June/Sept lows, if now worse.
