Fuzzybear… That Wikipedia example is a bearish pennant, but pennants can also be bullish.
For Pennants, the price trendlines tend to converge. At the start of the Pennant, the price spikes, perhaps in response to a favorable product or earnings announcement. Following the price spike, the price fluctuations continue until they taper out and become decreasingly less volatile. This behavior appears on a price chart with the initial price spike forming what technical analysts refer to as the “mast” of the Pennant, followed by a triangular pennant shape.
As the Pennant develops, the volume tends to decrease. Martin Pring notes in his book, Technical Analysis Explained, “a pennant is in effect a very small triangle. If anything, volume tends to contract even more during the formation of a pennant than during that of a flag.” However, as with Flags, when the Pennant completes you will often observe a sharp spike in volume. Duration of the Pattern
In his book, Technical Analysis of the Financial Markets, John J. Murphy identifies that Pennants and Flags are relatively short-term and should be completed within one to three weeks". He also notes that by comparison, the bullish patterns take longer to develop than the related bearish patterns.
It is commonly held that the length of the mast indicates the potential price increase. Like the Flag, the Pennant is considered to be a pause in an uptrend. Following the Pennant, the price typically jumps to replicate the height of the mast, while continuing in the direction of the inbound trend.