SMI 30m With Built-in Divergence Alerts

Stochastic Momentum Index SMI 30m is a simplified, single-timeframe Stochastic Momentum Index (SMI) designed for traders who want a clean momentum oscillator with clear crossover signals and automatic higher-timeframe filtering.
This version is locked to a 30-minute timeframe, making it consistent across any chart you place it on.

The script plots:

SMI Blue Line – the main momentum line

SMI Orange Line – the signal line (EMA-smoothed)

Overbought / Oversold regions

Optional colored background zones that highlight strong momentum extremes

Both the Blue and Orange plots are fully exposed, allowing users to manually create TradingView alerts for crossovers.
Additionally, the script includes two built-in alert conditions for traders who prefer automatic signals.

How the SMI is calculated

This script uses a double-EMA smoothing method to stabilize momentum:

Highest and lowest price ranges are calculated over the selected %K period.

Relative position of price inside that range is computed.

A double EMA is applied to both the range and the midpoint offset.

The SMI result is scaled to ±200 for clarity.

The Signal Line is a single-EMA applied to the SMI.

These parameters can be adjusted:

%K Length

%D Length

EMA Length

The default values match traditional 13-3-3 SMI settings.

Visual Components
1. SMI Blue Line

Represents the primary momentum movement.
Values above 40 indicate positive momentum; values below −40 indicate negative momentum.

2. SMI Orange Line

Acts as a smoothing signal line.
Crossovers between Blue and Orange often indicate momentum shifts.

3. Overbought / Oversold Zones

+40 = overbought boundary

−40 = oversold boundary
These levels help identify exhaustion points.

4. Gradient High/Low Zones

The script includes colored fill zones above +40 and below −40 to visually highlight extreme momentum regions.

Built-In Alerts

The indicator includes two pre-configured alert conditions:

1. Bearish Cross (Overbought)

Triggers when:

The Blue SMI crosses below the Orange SMI

AND the Blue SMI value is above 80

This represents a potential bearish divergence or momentum reversal from extreme highs.

Alert title:
SMI Bearish Cross

2. Bullish Cross (Oversold)

Triggers when:

The Blue SMI crosses above the Orange SMI

AND the Blue SMI value is below −80

This represents a potential bullish divergence or reversal from extreme lows.

Alert title:
SMI Bullish Cross

How to Use Alerts

After adding the indicator to your chart:

Open the Alerts panel

Select Condition → SMI (1 TF) 30m

Choose either:

SMI Bearish Cross

SMI Bullish Cross

Set your preferred trigger method:

Once per bar close

Once per bar

Once per minute

Create the alert

Traders can also manually create alerts for:

Blue crossing above Orange

Blue crossing below Orange
Because both plots are fully exposed.

Purpose

This indicator is intended for traders who want a stable, single-timeframe SMI with:

Clear structure

Extreme-zone highlighting

Exposed plots for custom alerts

Built-in reversal alerts

Consistent 30-minute TF regardless of chart

It can be used for:

Identifying trend reversals

Detecting momentum exhaustion

Confirming entries/exits

Spotting early divergence signals