The trade set up is based on VSA, Volume Spread Analysis, which states that for any substantial move in the price to any direction must supported by a market shake out such as short or long covering aggressively for the purpose of liquidity grab. This is the Newton's Law in the Financial Market. For every action there is a rection. Hence, for the PA to move higher, there must be a liquidity grab, either you are part of it, or you are watching it happen. The best entry level is once the shake out is confirmed, according to Wyckoff.