The Upside Gap Two crows is a three candlestick  trend reversal pattern. 
This pattern occurs after an uptrend.Day1 has a longer bullish  candlestick. Second day candlestick is a gapped up bearish candlestick and the real body should be above the real body of the first day’s candlestick. Day3 candlestick is a bearish candlestick that gaps up from the Day2 candlestick and closes below the close Day2 candlestick. Day3 candlestick basically engulfs the real body of Day2 real body. 

  
Psychology of Piercing pattern is that on day one bullish candlestick  confirms the previous uptrend. On Day2 the price of the security gaps up to indicate bulls  are dominating  but instead the price of the security closes bearish but still higher than the Day1 closing price. On Day3  bulls attempt to take the prices again with the gap up but the bears take control and  push the price of the security down  below the real body of Day2.  As bears are able to push the prices down in two successive days, this indicates the price of the security can be expected to go down or move sideways. 

As like any other, Upside Gap two crows  require confirmation candlesticks in the following days. If future day candlesticks go above  the Day3 candlestick  then the pattern is voided. 

Practice Upside Gap Two Crows – Beginner