GBPUSD is facing the resistance of the downward trend line on 4-hour chart. As long as the trend line resistance holds, the rise from 1.5951 could be treated as consolidation of the downtrend from 1.6524, another fall to 1.5600 area is still possible. On the upside, a clear break above the trend line resistance will indicate that the downtrend had completed at 1.5951 already, then the following upward movement could bring price to 1.6400 zone.