Double top and bottom patterns are chart patterns that occur when the underlying investment moves in a similar pattern to the letter "W" (double bottom) or "M" (double top). Double top and bottom analysis is used in technical analysis to explain movements in a security or other investment, and can be used as part of a trading strategy to exploit recurring patterns.
Double top and bottom patterns typically evolve over a longer period of time, and do not always present an ideal visual of a pattern because the shifts in prices don't necessarily resemble a clear "M" or "W". When reviewing the chart pattern, it is important for investors to note that the peaks and troughs do not have to reach the same points in order for the "M" or "W" pattern to appear.
Double top and bottom patterns are formed from consecutive rounding tops and bottoms. These patterns are often used in conjunction with other indicators since rounding patterns in general can easily lead to fakeouts or mistaking reversal trends. (See also: Analyzing Chart Patterns: Double Top and Double Bottom)
A double top pattern is formed from two consecutive rounding tops. The first rounding top forms an upside-down U pattern. Rounding tops can often be an indicator for a bearish reversal as they often occur after an extended bullish rally. Double tops will have similar inferences. If a double top occurs, the second rounded top will usually be slightly below the first rounded tops peak indicating resistance and exhaustion. Double tops can be rare occurrences with their formation often indicating that investors are seeking to obtain final profits from a bullish trend. Double tops often lead to a bearish reversal in which traders can profit from selling the stock on a downtrend.
Double bottom patterns are the opposite of double top patterns. Results from this pattern have the opposite inferences. A double bottom is formed following a single rounding bottom pattern which can also be the first sign of a potential reversal. Rounding bottom patterns will typically occur at the end of an extended bearish trend. The double bottom formation constructed from two consecutive rounding bottoms can also infer that investors are following the security to capitalize on its last push lower toward a support level. A double bottom will typically indicate a bullish reversal which provides an opportunity for investors to obtain profits from a bullish rally. After a double bottom, common trading strategies include long positions that will profit from a rising security price.