RSI Alert Indicator: Overbought and Oversold Crossings

Written by Dominic Walsh · Published 8 Jul 2026 · Last updated 20 Aug 2026

The RSI alert indicator plots one relative strength index line in its own pane. It watches that line for moves into the overbought and oversold zones. Three inputs drive both the line and the messages. It suits traders who want a plain read on price with an alert.

This build ships as rsi-alert-indicator-indicator-forexmt4systems.ex4 for MT4 and rsi-alert-indicator-indicator-forexmt4systems.ex5 for MT5.

Platforms	MT4 (.ex4) + MT5 (.ex5)
Chart window	Separate window
Plots	1: RSI
Alerts	popup, push notification, email, sound
Inputs	9

What the RSI Alert Indicator draws on the chart

One buffer holds everything. The plot labelled RSI runs sea green in a separate window. It moves between zero and one hundred under the price chart.

The pane carries no level lines of its own. OverboughtLevel and OversoldLevel steer the alert test only. Add horizontal lines by hand to see the zones on the pane.

No marks or objects reach the price chart. The line is the whole visual.

• RSI: plot, sea green

How the RSI Alert Indicator calculates its values

Gains and losses over the window

The sum comes first. For each bar the code walks back across the window. It adds every rise from one close to the next into one total. Every fall goes into another total.

Relative strength comes from the ratio between them. Dividing total gain by total loss gives that ratio. The formula turns that ratio into a number from zero to one hundred. A window with no down close returns one hundred outright.

A simple average, not Wilder smoothing

The averaging matters. This build sums the window and divides once. That is the Cutler variant of the relative strength index. Wilder’s original carries the previous average forward and folds each new bar into it.

The two versions track each other closely but not exactly. A spike lifts the simple version at once. It leaves in one step when that bar drops out of the window. The smoothed version fades it gradually.

The crossing test

Alerts watch the last two readings. A buy message fires when the line moves down through OversoldLevel. A sell message fires when the line moves up through OverboughtLevel.

That direction catches some traders out. The message marks entry into a zone rather than exit from it. A buy message therefore arrives while momentum still points down.

How to read the signals

A reading under the oversold mark says sellers pushed hard all window. It does not say a bottom formed. Many traders wait for the line to climb back out.

The two zone settings sit at different distances from the midpoint. Twenty five and seventy leave a wider lower zone. That arrangement fires fewer buy messages than a symmetric pair would.

Divergence still works on this line. A lower price low against a higher line low is the classic reading. The pane shows it with no extra tools.

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

Crossings into either zone can raise a popup, a push notification, an email or a sound. Each closed bar carries at most one message.

Every RSI Alert Indicator input

Core settings

Setting	What it does	Default
Period	Bars of closing change behind each reading. The shipped count matches the usual fourteen.	14
OverboughtLevel	Upper trigger for the sell message. Move it higher on trending instruments.	70
OversoldLevel	Lower trigger for the buy message. The shipped value sits below the usual thirty.	25

Alert settings

Setting	What it does	Default
EnableAlerts	(see inputs panel)	on
EnablePopup	(see inputs panel)	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

This line suits any liquid market. The pane reads the same on every chart. On M5 the line swings through both zones many times a session. H4 and D1 leave a handful of crossings a month. Traders who add a trend filter tend to work H1 and above. Set your own horizontal lines to match the thresholds you settle on.

When the RSI Alert Indicator fails

Strong trends pin the line. Price grinding higher for days keeps the reading near the upper threshold. Every message that fires there argues against a move still running.

A short window turns noisy fast. Cutting the sample makes the line reach both zones on ordinary bars. The message count climbs while the signal gets worse.

The trigger catches the wrong moment for some plans. Traders who want the exit from oversold have to watch the pane themselves. Nothing fires on the way back out.

The simple average reacts to bars leaving the window. One large candle shifts the reading when it drops off the back end. That happens even though nothing moved on the current bar.

Copy rsi-alert-indicator-indicator-forexmt4systems.ex4 into MQL4/Indicators and rsi-alert-indicator-indicator-forexmt4systems.ex5 into MQL5/Indicators, then restart the terminal and drag the RSI Alert Indicator onto a chart. The step-by-step guide with screenshots is at how to install MT4 and MT5 indicators.

Download the RSI Alert Indicator for MT4 and MT5

The zip rsi-alert-indicator-indicator-forexmt4systems.zip holds rsi-alert-indicator-indicator-forexmt4systems.ex4, rsi-alert-indicator-indicator-forexmt4systems.ex5 and a short README, compiled files only. Enter your email below and the download link arrives in your inbox.

FAQ

Why does OversoldLevel sit further from the midpoint than OverboughtLevel?

The build ships an uneven pair on purpose. Twenty five sits further from fifty than seventy does. The lower zone takes a deeper push to reach. That cuts buy messages on choppy charts. Set both the same distance apart if you prefer the textbook pair.

Does this RSI match the one built into MetaTrader?

Closely, but not bar for bar. The platform version uses Wilder smoothing. That carries the old average forward. This build sums the window and divides once. Both track the same shape and reach the same zones. The smoothed line moves a little slower after a sharp candle.

Can I add OverboughtLevel and OversoldLevel lines to the pane?

Yes, by hand. The build sets no level lines of its own. Open the pane properties and add levels at the numbers you use. The reading then gets much easier to scan. The alert test never needs those lines, since it reads the input values direct.

How many closed bars does the RSI line need before it appears?

One full window plus the bar before it. Each reading compares one close with the next across the sample. On the shipped setting that means about fifteen bars of history. A fresh chart shows nothing until the terminal loads enough bars.

Are results guaranteed?

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