Quite possibly a bat pattern on the 1hr chart. We've seen quite a lot of resistance to break the 640 line, and a further push can lead to 625 where the 1.618BC extension is located. If by that time there's no reversal, we might be seeing a drop to 605 region, which in the past showed great resistance and would now serve as good support, and that is exactly where the extension of the bat pattern lays; on the 2.618BC or the .886XA, at this point you can go long and place a stop loss just beneath the XA (which happens to be 600).