Fair Value Gap vs Mitigation Block
Michael Whitman
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Trading since 2017, full-time since 2020
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Published 2026-09-08
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Updated
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Reviewed
A fair value gap is the strip of price skipped between the outer wicks of three quick candles, so it can be drawn before price comes back. A mitigation block is an area named after price has returned to it and reacted. On five-minute SPY bars, a return to a gap was the normal outcome, often within minutes.
Mitigation, in this vocabulary, means price coming back to an area left behind. A mitigation block is the area where that return produced a reaction. Since a fair value gap is also an area price is expected to come back to, the useful question is how often, and how fast, the return happens anyway.
What each one is
On a five-minute chart a fair value gap takes fifteen minutes to form. Three bars, with the first and third wicks apart; the strip between them is the gap once the third bar closes. Fair value gap covers the rule.
Mitigation blocks are areas named for a return and a reaction that already happened. Mitigation block explains why it can only be marked after the reaction it is named for, and the order block page covers its better-defined relative.
So one is a prediction-free measurement and the other is a label applied later. That difference decides which of the two can be counted before the outcome is known, and both get drawn on the same charts.
Where they differ
When each exists. The gap is complete at candle three’s close, whereas the mitigation block exists only once price has come back and moved away again.
What defines it. The gap is defined by two wicks, while a mitigation block depends on a prior move, the return, and a judgment about the reaction, and those details vary between teachers.
What a return means. For the gap, a return is simply the next thing that happens or does not, rather than a signal. For a mitigation block, the return plus reaction is the definition.
What can be tested. Returns to gaps can be counted on any chart, but neither kind of block can be counted without first deciding what counts as a reaction, which most descriptions never state.
Which one to use: Fair Value Gap or Mitigation Block?
Mark the fair value gap when the area has to exist in advance and be checked later against what happened.
Use the mitigation idea only with a written reaction rule rather than a feeling, for example a close back outside the band within a set number of bars.
When you trade intraday, expect the return and plan for the reaction. On five-minute SPY the return came most of the time, so the return alone cannot separate one area from another; either kind of area gets one.
How fast price came back on a five-minute chart
The test. SPY five-minute bars in regular hours, 60 sessions running 10 July through 2 October 2026, at 78 bars each. A gap uses three bars of the same session; a return is a later bar of that session trading into the band, and a full fill is a bar trading through its far edge. Nothing carries overnight.
909 gaps formed, a median of 15 a session. 749 (82.40%) were re-entered before the close, 708 (77.89%) reached the band’s midpoint and 672 (73.93%) were filled all the way through.
Most returns were immediate. 403 gaps (44.33%) were re-entered by the very next bar, 539 (59.30%) within 15 minutes, 604 (66.45%) within 30 minutes and 675 (74.26%) within an hour. The median wait among returns was 5 minutes, and the median time to a full fill 15.
What the gaps that were left alone had in common
Time was not the reason. The 160 gaps never revisited had a median of 35 bars, close to three hours, left in the session when they formed.
Time of day mattered a little. Gaps formed before noon were revisited 84.93% of the time (310 of 365); gaps formed from 2 pm on, with less session left, 77.73% (199 of 256).
A slow return from 2 October 2026. A bearish gap formed between the 10:55 and 11:05 bars, with a band from $770.04 to $770.75. Price did not come back until the 13:00 bar, whose high of $770.05 reached the band by one cent, and it never filled before the close. That is the kind of brief touch a mitigation reading would call a reaction, and it is also the kind the clock produces on its own.
The original data
The sample. SPY five-minute bars from Yahoo Finance, regular hours, 78 a session for 60 sessions, 10 July to 2 October 2026: 474 bullish and 435 bearish gaps with a median width of 15 cents. Sixty sessions is a small sample from a single stretch of one year; another quarter could look different.
The headline figure. 82.40% of five-minute gaps were re-entered the same session; half of those returns came on the next bar.
The file. Every gap with its session, time, band and minutes to the first return and the full fill is in the SPY five-minute gap file.
What is left out. No reaction is scored, because the mitigation idea gives no fixed rule for one, and no trade is simulated. Daily charts behave differently; this is one intraday timeframe.
When it fails
The failure is counting the return as proof the area mattered. Draw boxes on five-minute gaps, watch price come back to most of them within minutes, and every box looks respected. Then the ones followed by a bounce get named mitigation blocks and the rest are forgotten. The return was built into the timeframe; only a reaction defined in advance can tell areas apart.
The second failure is marking the block after the bounce. The label then fits every chart.
A third is ignoring width. A 15-cent band is inside the noise of one bar.
A fourth is carrying intraday gaps overnight. The next open can skip them.
And a fifth is trusting a quarter’s sample. Sixty sessions is a small window.
Related
Fair value gap has the three-candle rule. Mitigation block explains the after-the-fact label. And order block covers the candle rule both ideas grew from.
On a five-minute chart, do not read price coming back to a gap as a sign. It came back most of the time, usually within a few bars. If you want to call an area a mitigation block, write down beforehand what reaction you need to see, and how big.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.