Bat Harmonic Pattern Indicator Access Indicator: XABCD

Written by Dominic Walsh · Published 28 May 2026 · Last updated 26 Aug 2026

The bat harmonic pattern indicator access indicator hunts one shape. Five pivots form four legs. Each leg gets measured against the one before it. Only ratios inside the four bands earn a mark at point D.

This build ships as a compiled .ex4 for MT4 and .ex5 for MT5; the screenshots below come from EURUSD H4.

Platforms	MT4 (.ex4) + MT5 (.ex5)
Chart window	Main price chart
Plots	3: XABCD, Buy, Sell
Alerts	popup, push notification, email, sound
Inputs	16

What the Bat Harmonic Pattern Indicator Access Indicator draws on the chart

A dark orange `XABCD` zigzag joins the five pivots.

`Buy` uses arrow 233 in lime and `Sell` uses 234 in red.

Text objects label the points on the chart.

Each mark sits `ArrowOffsetPoints` `50` points from the candle at D.

• XABCD: zigzag, dark orange, width 2
• Buy: arrow, lime, width 4, arrow code 233
• Sell: arrow, red, width 4, arrow code 234

How the Bat Harmonic Pattern Indicator Access Indicator calculates its values

Fractal pivots first

`Depth` `7` decides a fractal high or low. The code keeps up to `MaxPivots` `40` of them and works backward through that list.

Four ratio bands

AB against XA must land between `AbLo` `0.35` and `AbHi` `0.55`. BC against AB must land between `BcLo` `0.3` and `BcHi` `0.9`. CD against BC must land between `CdLo` `1.6` and `CdHi` `2.65`.

Tolerance widens each band

`RatioTol` `0.12` gets added at both ends of every band. Real price rarely lands on a textbook ratio, so a hard edge would find almost nothing. That slack is why matches appear at all.

How to read the signals

A mark lands at D, the last pivot of the five.

The zigzag shows exactly which legs the ratio test used.

D sitting at a swing low gives the bullish case.

Legs come from fractals, so a pattern completes several bars after D forms.

Alert channels in this build: popup, push notification, email and sound, one message per closed bar.

`EnableAlerts` is the master toggle and starts true, with `EnablePopup` giving the terminal window. `EnablePushNotify` handles mobile, `EnableEmail` handles mail and `EnableSound` plays `SoundFile`. Those three arrive off. Alerts wait for a bar to close.

Every Bat Harmonic Pattern Indicator Access Indicator input

Core settings

Setting	What it does	Default
Depth	Bars either side that confirm a fractal, default `7`.	7
MaxPivots	How many pivots stay in the working list, default `40`.	40
AbLo	Floor for the AB against XA ratio, default `0.35`.	0.35
AbHi	Ceiling for that same ratio, default `0.55`.	0.55
BcLo	Floor for the BC against AB ratio, default `0.3`.	0.3
BcHi	Ceiling for that same ratio, default `0.9`.	0.9
CdLo	Floor for the CD against BC ratio, default `1.6`.	1.6
CdHi	Ceiling for that same ratio, default `2.65`.	2.65
RatioTol	Slack added to both ends of every band, default `0.12`.	0.12

Display settings

Setting	What it does	Default
ArrowOffsetPoints	Points between the mark and the candle at D, default `50`.	50

Alert settings

Setting	What it does	Default
EnableAlerts	Master toggle for pattern alerts, default `true`.	on
EnablePopup	Terminal window on a completed pattern, default `true`.	on
EnablePushNotify	(see inputs panel)	off
EnableEmail	(see inputs panel)	off
EnableSound	(see inputs panel)	off
SoundFile	(see inputs panel)	alert.wav

Settings that fit your chart

The screenshot note picks H4 for clean, well separated legs. Harmonic shapes want room, and a fractal at `Depth` `7` needs seven bars either side. On M5 the legs blur together. Daily bars give very few patterns a year.

When the Bat Harmonic Pattern Indicator Access Indicator fails

A fractal at depth seven confirms seven bars late, so D is history by the time it marks.

`RatioTol` `0.12` is generous, which lets shapes through that a purist would reject.

Only one ratio set ships here, so other harmonic shapes go unmarked.

Copy the compiled Bat Harmonic Pattern Indicator Access Indicator file into your MQL4/Indicators folder, and the MT5 build into MQL5/Indicators, then restart the terminal and drag it onto a chart. The step-by-step guide with screenshots is at how to install MT4 and MT5 indicators.

Background reading on the method behind the Bat Harmonic Pattern Indicator Access Indicator: Ultra-low latency direct market access on Wikipedia, Speed Resistance Lines at StockCharts ChartSchool.

Download the Bat Harmonic Pattern Indicator Access Indicator for MT4 and MT5

The zip holds the compiled Bat Harmonic Pattern Indicator Access Indicator build for MT4 and MT5, plus a short README. Compiled files only, no source. Enter your email below and the download link arrives in your inbox.

FAQ

What does Depth 7 define?

A fractal pivot. The bar has to beat seven bars on each side before it counts as a swing point. That makes pivots reliable and late in equal measure, since seven newer bars must close first.

How wide does RatioTol 0.12 make each band?

It adds twelve hundredths at both ends. So the AB band of `0.35` to `0.55` effectively runs from 0.23 to 0.67. Real swings rarely hit a textbook ratio, and without that slack matches would be extremely rare.

What decides a Buy rather than a Sell?

Where point D sits. A D that is a swing low gives the bullish case and fills the buy plot. A D at a swing high fills the sell plot. The ratio test itself is identical for both.

Why is ArrowOffsetPoints 50 so large?

Because harmonic legs on H4 cover a lot of ground, and a small gap would bury the mark in the candle. Fifty points reads well on a four-hour chart. Reduce it if you drop to a faster timeframe.

Are results guaranteed?

No. Trading involves risk. Results are not guaranteed; past performance is not indicative of future results. Use the Bat Harmonic Pattern Indicator Access Indicator as one input. Always backtest before trading live.