Spike (Market Profile)
In Market Profile, a spike is a late-session move away from the day's value, typically in the last bracket or two, that has not had time to be accepted or rejected before the close. The next session's open relative to the spike is read with the spike rules: above it is the strongest response, inside it a neutral one, below its base the weakest.
Senzoukria · Glossary · Updated September 2026
Definition
Most of a session's value is built over many brackets. A spike is the exception: a directional move in the final part of the session, often on single prints, that leaves a narrow extension of the profile beyond the day's value. Because the market closed before responding to it, the spike is an open question: the next session will either accept the new prices or reject them. The spike's base is the price where it started; its top is its extreme.
The spike rules
| Next open | Reading |
|---|---|
| Above the top of the spike | Most positive: the new prices were accepted overnight |
| Inside the spike | A neutral response; building value inside it shows acceptance of the probe |
| Below the base of the spike | Most negative: the late probe is rejected |
A worked example
A regular session from 8:30 to 15:00 Chicago time has 13 half-hour brackets, A to M. Value has formed between 5,000.00 and 5,020.00 for most of the day. In bracket M, price rallies from 5,020.00 to 5,031.00 on single prints. The spike runs from its base at 5,020.00 to its top at 5,031.00, and Dalton's guidelines treat the base as support. If the next session opens at 5,033.00, above the spike, the probe was accepted. If it opens at 5,026.00, inside the spike, the response is neutral and the question becomes whether value builds there. If it opens at 5,016.00, below the base, the late rally is rejected.
Limits
- The rules describe the opening response, not the rest of the session.
- A spike made on a news release at the close carries different information from one made by position squaring.
- The definition depends on the session: a spike at the end of the regular session is continued by the overnight trading, which is why the open is judged after it.
In Senzoukria
On the Market Profile (TPO) overlay with the 'RTH indices (8:30–15:00 CT)' period and 'TPO letters', a spike appears as the last letters of the profile extending beyond its value area. The overlay's structure rules treat a run of single-bracket rows at an extreme as a tail, so 'Single prints & tails' marks the spike, and 'Extend single prints' carries dotted lines from those rows into the next profile. 'Open & close markers' show where the next profile opened relative to them. Recognizing that those single prints were made in the final bracket, and therefore form a spike rather than a finished rejection, is left to the reader.
Related
- Single print
- Excess
- Acceptance and rejection
- Market Profile open types
- Market profile
- Market Profile (TPO) documentation
In the same section
Sources
- Jim Dalton Trading: spike guidelines (2026-09-25)
This page in other languages
Frequently asked questions
- How is a spike different from a tail?
- Both are single prints at an extreme. A tail usually records a rejection: price reached those prices and left them. A spike records a move made just before the close that has not yet been tested, so its meaning is only settled by the next session's response.
- What does it mean when the market opens inside the spike?
- It is the neutral case in the spike guidelines: the market neither accepted the new prices outright nor rejected them. Watching whether value builds inside the spike, and whether its base holds, gives the next piece of evidence.