Longest-Bar Test
Elliott Wave Theory glossary · Elliott Wave Theory
Definition
A trend-damage diagnostic articulated by W. D. Gann and adapted into Elliott practice: identify the longest single price bar within a trending move (the session of maximum directional conviction), then watch for any subsequent counter-trend bar that exceeds its length. When a counter-trend bar surpasses the benchmark, the trend is signalling potential exhaustion — historically reliable at Wave 5 extremes, as during the October 1929 crash.
Longest-Bar Test in plain English
During a strong trend, one price bar (a single day or session's up-and-down range) is usually taller than all the rest — that's the moment the crowd was most convinced and pushing hardest, so it acts as a benchmark of the trend's strength. The longest-bar test says: keep watching, and the first time a bar moving the OPPOSITE way grows longer than that benchmark, the trend may be running out of gas. It's like an arm-wrestling match where one side's biggest surge gets suddenly out-muscled by the other side — a sign momentum has flipped. Originally from trader W. D. Gann and folded into Elliott practice, it's proven handy for spotting exhaustion at the end of a wave 5, famously around the October 1929 crash.
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