GBPUSD stays in a upward price channel on 4-hour chart, and remains in uptrend from 1.6692, the fall from 1.7179 could be treated as consolidation of the uptrend. Support is located at the bottom of the channel, as long as the channel support holds, the uptrend could be expected to resume, and next target would be at 1.7300 area. On the downside, a clear break below the channel support will indicate that the uptrend had completed at 1.7179 already, then the pair will find support around 1.6850.
