Chart Patterns: What the Evidence Says

Chart patterns — head-and-shoulders, double tops and bottoms, triangles, flags, cup-and-handle — are the oldest documented family of trading signals, with a practitioner literature stretching back to the 1930s. They are also the family academics were most skeptical of, partly because "a head-and-shoulders" is hard to define precisely enough to test.

The evidence is mixed — and that's the point