What Is a Bullish Flag? Bullish flag formations are found in stocks with strong uptrends and are considered good continuation patterns. They are called bull flags because the pattern resembles a flag on a pole. The pole is the result of a vertical rise in a stock and the flag results from a period of consolidation. The flag can be a horizontal rectangle but is also often angled down away from the prevailing trend. Another variant is called a bullish pennant, in which the consolidation takes the form of a symmetrical triangle.