Bid Ask Spread Indicator: Your Trading Cost, Bar By Bar

Written by Dominic Walsh · Published 30 Jul 2026 · Last updated 9 Sep 2026

The bid ask spread indicator watches what a trade costs you. Each bar gets its spread plotted as a column in points. A column past `InpSpreadLimit` `25.0` turns red, so a widening spread is impossible to miss.

This build ships as a compiled .ex4 for MT4 and .ex5 for MT5; the screenshots below come from EURUSD H1.

Platforms	MT4 (.ex4) + MT5 (.ex5)
Chart window	Separate window
Plots	3: Spread, Wide Spread, Spread MA
Alerts	popup, push notification, email, sound
Inputs	11

What the Bid Ask Spread Indicator draws on the chart

A dodger blue `Spread` column shows the spread for each bar.

Past the limit a red `Wide Spread` column takes over.

A gold `Spread MA` line gives the typical cost across `InpMaPeriod` `30` bars.

The corner panel prints live bid, ask, spread and the running average.

• Spread: histogram, dodger blue, width 2
• Wide Spread: histogram, red, width 2
• Spread MA: line, gold, width 1

How the Bid Ask Spread Indicator calculates its values

History comes from the terminal

MetaTrader stores a spread figure with every bar. The code reads that series straight out, so the columns behind the current candle are what your broker actually charged at the time.

The live figure is measured directly

For the bar still forming, the code subtracts bid from ask and divides by the point size. That gives the same units as the history, so the panel and the columns agree.

One threshold splits the colour

`InpSpreadLimit` `25.0` decides which of the two column buffers receives the value. Both hold the same number. Only the colour differs, so the columns can never disagree at the switch.

How to read the signals

Column height is the cost of opening a trade on that bar.

The gold line is your normal cost, so compare against it rather than against zero.

Red clusters usually mark news, rollover or thin liquidity.

`ShowPanel` hides the readout when the chart gets crowded.

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

`EnableAlerts` controls the whole set and arrives true, with `EnablePopup` giving the terminal box. `EnablePushNotify` reaches a phone, `EnableEmail` sends mail and `EnableSound` plays `SoundFile`. Those three start off. The check fires at most once per bar.

Every Bid Ask Spread Indicator input

Core settings

Setting	What it does	Default
InpMaPeriod	Spread moving-average period. Bars behind the typical-cost line, default `30`.	30
InpSpreadLimit	Wide-spread limit (points). Points above which a column turns red, default `25.0`.	25.0

Display settings

Setting	What it does	Default
ShowPanel	Show Bid/Ask/Spread panel. Print the live bid, ask and spread readout, default `true`.	on
PanelCorner	Corner (0=UL,1=UR,2=LL,3=LR). Which corner the readout anchors to, default `0`.	0
PanelBg	Readout background colour, default `clrBlack`.	black

Alert settings

Setting	What it does	Default
EnableAlerts	Master control over every alert route, default `true`.	on
EnablePopup	Terminal box when the spread goes wide, default `true`.	on
EnablePushNotify	Phone alert when the spread goes wide, default `false`.	off
EnableEmail	Mail when the spread goes wide, default `false`.	off
EnableSound	Clip when the spread goes wide, default `false`.	off
SoundFile	(see inputs panel)	alert.wav

Settings that fit your chart

Spread matters most where it is large against your target. EURUSD H1 is the reference chart, and majors sit at the tight end. Exotics and indices run far wider. On M1 the same cost eats a much bigger share of the move.

When the Bid Ask Spread Indicator fails

Spread is broker specific, so a limit tuned on one account misleads on another.

The stored history is one figure per bar, not the worst spread inside it.

`InpSpreadLimit` `25.0` counts points, so it needs changing per instrument.

Copy the compiled Bid Ask Spread 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.

Download the Bid Ask Spread Indicator for MT4 and MT5

The zip holds the compiled Bid Ask Spread 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 InpSpreadLimit 25.0 count?

Points, not pips. On a five-digit currency pair twenty-five points is two and a half pips. Set it a little above your normal spread so the red columns mark genuinely unusual conditions rather than every busy hour.

Why does the Spread MA line matter?

Because a raw number means nothing on its own. Thirty bars of average cost tells you what normal looks like on this instrument and this session. A column well above that line is the one worth reacting to.

Where does the historical Spread column come from?

The terminal keeps a spread value alongside every bar it stores, and the code reads that series. So the history is your broker’s own record rather than a reconstruction, which is why it can differ between accounts.

Does ShowPanel affect the columns?

No. It only hides the corner readout with the live bid, ask and average. The pane keeps plotting either way. Turn it off when you already have other panels competing for the same corner.

Are results guaranteed?

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