Ichimoku Kinko Hyo views deviations away from its cloud ("kumo") as movement away from dynamically-rendered market equilbrium. Where these deviations become extreme in a market/instrument, some reversion toward the cloud to burn off the disequilibrium will occur.
Since the 2009 low, these deviations have only occasionally breached >20%. Across those occurrences considered here, the average deviation is 17.25%; whereas the average correction measures -9.8%. The deviation presently underway peaked yesterday at 18.6%.