Order Block Detector - indicator for MetaTrader 5

Order Block Detector

The idea behind it

Before a strong impulsive move, there is usually one last candle going the "wrong" way — the final sell candle before price rips higher, or the final buy candle before price collapses. That candle is read as the footprint of the order flow that fueled the move: the zone it occupies is where a large position was likely built before the breakout. This indicator formalizes the detection in three steps: confirm genuine fractal swing points, watch for a close that breaks decisively past one of them with a real-bodied impulse candle (not a weak doji push), and then look backward from that break for the last opposing candle — that candle's range becomes the order block.

Like the gap and liquidity-sweep detectors in this series, a zone here is genuinely live: while unmitigated it keeps stretching forward to the current bar, and the instant price trades back into it, the box freezes exactly at that bar and (by default) turns gray — so at a glance you can tell which zones are still "untested" and which have already been revisited.

How to interpret it

• Bullish order block (default green/white) — the last down-closing candle before an impulsive close above a recent swing high. Untested supply-turned-demand; often watched as potential support on a pullback.
• Bearish order block (default red) — the last up-closing candle before an impulsive close below a recent swing low. Untested demand-turned-supply; often watched as potential resistance on a bounce.
• An extending (colored) zone — still unmitigated; its right edge keeps moving forward live with InpExtendUntilMitigated enabled (default), or stops after a fixed InpExtendBars bars if disabled.
• A frozen, gray zone — price has traded back into it — the block is mitigated, and its box stopped exactly at that bar. Set InpHideMitigatedOBs to delete mitigated zones instead of graying them out.
• "Break" candle vs. the order block itself — the order block is the opposing candle, not the impulsive one; the impulsive candle is only used to confirm the structure break and is never drawn as a zone itself.

External variables (inputs)

Recommended use

Works on any symbol and any timeframe; structure-break and order-block concepts are pure price action with no symbol-specific assumptions, though — like any fractal-pivot method — InpSwingLookback trades off level significance against detection frequency the same way it does in this series' Liquidity Sweep Detector. Structure breaks and mitigation are both evaluated only on fully closed bars by design, so a block will not appear or disappear mid-candle while the current bar's high/low/close are still changing.

InpMinImpulseBodyPercent exists specifically to avoid tagging a barely-there close as a "break" — a candle that only just pokes past a swing level with a large wick and a small body is excluded, since that is closer to noise than genuine displacement. On very long chart histories, InpMaxOBsToTrack keeps the object count bounded rather than letting every historical order block accumulate indefinitely. This indicator only reads price data and never places, modifies, or closes any order, so it is safe to run on any account type.

All chart objects are created under a single internal name prefix and are fully removed via ObjectsDeleteAll() in OnDeinit() when the indicator is detached, so it leaves nothing behind on the chart.

Fig. 1. A bullish order block confirmed by the impulsive break candle, later mitigated, on XAUUSD M15. Rendered in black and white per the Code Base image guidelines (750×500 px).