The tendency for one of the three impulse waves (1, 3, or 5) to become significantly larger than the other two.
Description
In an impulse wave, one of the three actionary waves (wave 1, 3, or 5) often becomes elongated — a phenomenon called extension. Extensions are most common in wave 3. In commodity markets, wave 5 extensions are frequently observed. Wave 1 extensions are the rarest. When one wave extends, the other two actionary waves tend to become equal in price movement and duration (the guideline of equality). In the extended wave, all five sub-waves become clearly visible and roughly equal in length.
Key Points
- Only one of waves 1, 3, or 5 extends in a given impulse — never two
- Wave 3 extensions are most common; wave 5 extensions are common in commodities; wave 1 extensions are rare
- When one wave extends, the other two actionary waves tend to be equal in size
- All five sub-waves of the extended wave become visible and roughly equal
- Extension increases the total sub-wave count: a normal impulse has 5 waves, but with an extended wave 3 the count becomes 9
