A top is a reversal pattern which can indicate that a contract is about to move against the previous trend.
A top pattern has three peaks -- two smaller ones on the sides and one larger one in the middle.
First, a contract rises to a new high and then falls back to a new low (the "neckline," which marks support). Then, the contract hits an even higher high before dropping back down to the previous low. The right shoulder is formed when the contract rises back up but not as high as the previous high, and then falls back down to the low. The pattern is complete when the price breaks through the previous low, or the neckline.
The top pattern can indicate that a new downward trend is about to happen. Watch , as breakouts will tend to occur on high-volume moves.