Running corrections typically occur in markets that are “on the move.” In a bullish version after a five wave rally, a running flat correction will have down waves A and C, separated by a B wave. Wave C will end above the bottom of wave A, which is not typical in a regular flat or expanded flat. In both of those, wave C ends below the low of wave A but here the market forms a higher high – higher low pattern instead. For instance, a bull market that is “on the move” will experience running corrections which don’t achieve much downside, making hard to get onboard the next wave of the bull move.
Read an in depth post about running flat correction with chart example and the pattern’s trading significance: How running corrections are born?