Core terms
Parabolic move
Trader shorthand for a price run that steepens, with bars climbing faster and ranging wider than before. It is measurable only through stated rate and range-expansion rules.
One measurable description, chosen rather than standard: price at least 40% above the regular-session open within 20 minutes or less, and each of the last three 1-minute bars with a high-to-low range at least twice the average of the ten bars before them.
Words such as "exhaustion", "blow-off" and "overextended" describe an end that is known only afterwards. A bar with the session's largest volume, a long upper wick or a first close below the prior bar's low fits a reversal and also a pause before another leg. A run can end in a LULD pause rather than a smooth turn, which makes stops costly for late longs and early shorts alike.
For context, with hindsight: among 69 gappers of 20% or more whose regular-session high was at least 50% above the open, 56 (81.2%) closed below the midpoint between open and high (2026-07-01 to 2026-10-02; FennEdge archive; as of 2026-10-02). Days were selected by their final high, so this describes how such days ended, not how a short entered during the run fared.
What traders should verify
Record the rate and range rule that made a move "parabolic", what was observable at the decision time, and a halt gap in the cost row before sizing either side.
Do not conflate
Trader usage; there is no official definition. "Overextended" has no fixed threshold, and a stock 50% above its open can go on to double. Labels such as "the top" applied after the fact are hindsight.
Primary source
Trader usage: there is no official definition, and platforms and tools may calculate it differently.