'A' a long signal
The commercials are extremely long and have greatly accelerated their buying during the previous six weeks (near 50% in the green line at the botton). Just before the the "A" signal, the price had been in a bearish trend. After the second time it exited above the bearish trend line (the first time would have resulted in a very small gain), a long entry could have been made on July 25, 2012. Holding that position until exiting, when big weakness appeared before September 13, 2012, would have resulted in a gain of $3,770 per contract.
'B' a short signal
The commericals are very short and the "trigger" - the green line at the bottom is at a very high reading. Short entry could have been made when the price broke below the bullish trend line on October 24,2014. Holding th short position until strength appeared on November 24, 2014 would have resulted in a gain of $1,780 per contract.