USDJPY is now in downtrend from 105.44, the price action from 100.75 could be treated as consolidation of the downtrend. Key support is at 100.75, a breakdown below this level will indicate that he downtrend has resumed, then the following downward movement could bring price to 90.00 area. Key resistance is at 105.44, only break above this level will indicate that the pair remains in uptrend from 93.79 (Jun 13, 2013 low), and the target would be at 110.00 zone.
