Crude oil tested a critical support level on the daily chart last session. This market has experienced such an aggressive sell off, it has forced price to accelerate away from its mean value - leaving that mean to price gap.
Generally when these gaps occur, the market likes to 'sling back' and fill the gap between mean and price which is knows as the 'elastic band effect'.
There is also a large bullish rejection candle off a strong support level which compounds the value of this trade idea.