What is a Bump-and-Run Reversal?
The bump-and-run reversal is a chart pattern that describes the end of an unsustainable acceleration. It begins with a lead-in phase, where price advances along an ordinary trendline at a modest angle. Then comes the bump: price steepens sharply away from that line, often on enthusiasm or speculation, climbing at an angle that cannot be maintained. The run is the resolution, when the accelerated advance fails, price falls back to the lead-in trendline, and a break of that line completes the reversal.
The pattern was introduced and named by Thomas Bulkowski, who framed it as a study of excessive speculation: the steeper the bump relative to the lead-in, the less sustainable the advance. His guideline calls for a lead-in trendline sloping at roughly 30 degrees and a bump phase steepening to roughly 45 to 60 degrees, with the bump's height at least about twice the lead-in height. The angles are chart-scaling artifacts, so most practitioners treat the ratios of heights, not literal degrees, as the working test.
Traders care about the pattern because it gives structure to something otherwise hard to time: the aftermath of a parabolic phase. Rather than shorting into strength, the bump-and-run template waits for the acceleration to fail and for the original trendline to break, which converts a vague sense of "overextended" into a defined trigger and invalidation. An inverted version, sometimes called a bump-and-run bottom, applies the same logic to overdone declines.
How to identify a bump-and-run reversal
The pattern is defined by the relationship between two phases, so identify the lead-in first and measure everything against it.
- 1Find a steady advance that respects an up-sloping trendline with several touches; this is the lead-in phase.
- 2Measure the lead-in height, the widest vertical distance from price to the trendline during that phase.
- 3Watch for the bump: price pulls away from the trendline at a visibly steeper slope, ideally with rising volume, until the distance above the line is at least about twice the lead-in height.
- 4Wait for the rollover: the accelerated advance stalls, sets a lower high, and price returns toward the lead-in trendline.
- 5The pattern completes when price breaks decisively below the lead-in trendline; some traders also wait for a failed retest of the broken line.
- 6Invalidate the read if price holds the trendline and resumes making new highs at a sustainable slope.
How traders use it
- Reversal entry on the trendline break: the standard tactic is to short (or exit longs) when price closes below the lead-in trendline after a mature bump, with a stop above the retest high.
- Profit protection in runaway longs: holders of a position that has gone parabolic can trail risk beneath the lead-in trendline, staying with the move while the acceleration lasts but exiting mechanically when it fails.
- Downside objectives: a common approach projects the bump height below the trendline break, in the spirit of the measure rule, though outcomes vary widely and partial retracements are common.
- Filtering: because steep advances sometimes keep going, many traders demand additional evidence such as climactic volume at the top or a clear lower high before acting; an early short into the bump itself is the pattern's most expensive misuse.
Bump-and-run vs. related structures
Rising wedge: A rising wedge is a decelerating advance squeezed between converging lines, while the bump-and-run is an accelerating advance pulling away from a single lead-in trendline before failing.
Parabolic phase: The parabolic phase describes the acceleration itself; the bump-and-run reversal is a specific template for how that acceleration ends, complete with a trigger line and invalidation.
V-top: A V-top reverses almost instantly with no lead-in structure to lean on; the bump-and-run offers the lead-in trendline as a reference the V-shape lacks.
Concept family
Chart & Candlestick Patterns
84 concepts mapped · 84 in the Library
Bump-and-run Reversal FAQ
Who invented the bump-and-run reversal pattern?
Thomas Bulkowski introduced and named it, originally studying it as a formation driven by excessive speculation. He also catalogued its statistics in his pattern research.
Do the 30 and 45 degree angles matter literally?
No. Trendline angles depend entirely on chart scaling, so the working test is relative: the bump phase should be visibly steeper than the lead-in and roughly twice its height or more.
Does the pattern work as a bottom?
An inverted version exists for overdone declines, where a down-sloping lead-in gives way to an accelerating sell-off that then fails back up through the line. It is less commonly discussed but follows the same logic.
When is the pattern invalidated?
If price returns to the lead-in trendline, holds it, and resumes the advance at a sustainable slope, the reversal case is off until a new bump and failure develop. No pattern outcome is assured.
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