Onyx Scalper Indicator for MT4 and MT5

Written by Dominic Walsh · Published 22 Jun 2026 · Last updated 21 Sep 2026

Be clear on the scope before loading it. The onyx scalper indicator has exactly one tuning input and one rule: a nine-bar RSI crossing the fifty line. No second filter, no trend check, no spacing between marks. What it does, it does in plain sight.

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	Main price chart
Plots	2: Onyx 50 Buy, Onyx 50 Sell
Alerts	popup, push notification, email, sound
Inputs	7

Plots this indicator declares

Two arrow plots, on price alone.

`Onyx 50 Buy` prints yellow using arrow 233.

`Onyx 50 Sell` prints slate blue using arrow 234.

Marks sit half a bar range from the candle.

No line and no pane appear anywhere.

Nothing plots the reading itself.

• Onyx 50 Buy: arrow, yellow, arrow code 233
• Onyx 50 Sell: arrow, slate blue, arrow code 234

The calculation, in order

Built in the file

Nothing calls the terminal indicator. `RsiPeriod` `9` bars of gains and losses get summed and divided inside this source, so the whole reading can be checked line by line.

The midline

Fifty is the only level. Crossing it upward prints the buy mark, and crossing down prints the sell. Neither overbought nor oversold enters the decision.

Placing the mark

Half the bar range does it. A buy sits that far below the low and a sell that far above the high, so spacing follows how large the bar was.

Reading it in practice

Fifty means gains and losses balanced over nine bars.

A crossing says that balance tipped.

Nine bars is short, so crossings come often.

Nothing spaces repeated marks apart.

Mark colours are unusual, yellow for buy.

The reading itself stays out of sight.

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

One event speaks here, a midline crossing, with `EnableAlerts` in charge and `EnablePopup` already showing a dialog. The phone, the mail queue and the desktop ring behind `SoundFile` all begin shut, and each crossing reports once a bar.

Every Onyx scalper Indicator input

Core settings

Setting	What it does	Default
RsiPeriod	Bars in the reading, `9`.	9

Alert settings

Setting	What it does	Default
EnableAlerts	Controls the crossing message, `true`.	on
EnablePopup	Shows it in a dialog box, `true`.	on
EnablePushNotify	Forwards it to a phone, `false`.	off
EnableEmail	Queues it for mail delivery, `false`.	off
EnableSound	Rings it on the desktop, `false`.	off
SoundFile	File behind that ring, `”alert.wav”`.	alert.wav

Getting the chart right

A nine-bar reading crossing its midline fires readily wherever you put it. EURUSD M15 suits the pace. On H1 the marks thin out to a few a day. On M5 they arrive often enough to need a filter you would have to add yourself.

The catch

A midline crossing is the weakest signal the reading offers.

Nothing filters a crossing in a flat market.

Repeated crossings print repeated marks.

One input leaves very little to tune.

Copy the compiled Onyx scalper 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 Onyx scalper Indicator: Relative strength index on Wikipedia, Scalping at BabyPips.

Download the Onyx scalper Indicator for MT4 and MT5

The zip holds the compiled Onyx scalper 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

Why does Onyx 50 Buy trigger on the midline?

Because fifty is where gains and losses over the window balance out. Crossing it says the balance tipped, which happens far more often than reaching an extreme and is a correspondingly weaker signal.

Does RsiPeriod 9 call the terminal indicator?

No. The gains, the losses and the division all run inside this source, so nothing depends on a built-in call and every step of the reading can be read in the file.

Where does the Onyx 50 Sell arrow get placed?

Half the bar’s own range above its high. The gap therefore grows on a large candle and shrinks on a small one, with no point setting to adjust when you move to another symbol.

Is RsiPeriod really the only tuning input?

For the calculation, yes. Nine bars is the only number that changes what gets drawn; everything else in the panel decides where messages go. Adding a filter means running a second tool beside it.

Are results guaranteed?

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