Accumulative Swing Index (ASI)

In this article, We learn about "Accumulative Swing Index (ASI)".Let's Go!

The Accumulative Swing Index (ASI) is a technical analysis tool that helps traders identify and quantify price trends in financial markets.

Developed by J. Welles Wilder Jr., the ASI calculates the cumulative sum of swing index values to generate a more comprehensive view of market trends.

Let’s discuss the concept, calculation, and application of the Accumulative Swing Index in trading.

What is the Accumulative Swing Index?

The ASI is a momentum oscillator that measures the strength of price swings in the market.

By accumulating the swing index values over time, the ASI provides a comprehensive view of the market’s overall trend direction and strength.

The ASI is particularly useful for identifying and confirming price breakouts and reversals, as well as assessing the potential for a trend continuation.

Calculating the ASI

The ASI calculation involves a series of steps:

Calculate the swing index (SI) using the following formula:

SI = 50 * (C – Cy + 0.5 * (C – O) + 0.25 * (Cy – Oy)) / R


C = current close price

Cy = previous close price

O = current open price

Oy = previous open price

R = the highest range value, selected from the following options:

  • (Current High – Current Close)
  • (Current Low – Current Close)
  • (Current High – Previous Close)
  • (Current Low – Previous Close)

Calculate the ASI by accumulating the swing index values:

ASI = ASI(previous) + SI(current)

Interpreting the ASI

When interpreting the ASI, traders should focus on the direction and magnitude of the index. The key aspects to consider include:

  • Trend Direction: A rising ASI indicates an uptrend, while a falling ASI suggests a downtrend. The ASI can be plotted on a chart along with the price to visually assess the trend direction.
  • Trend Strength: The magnitude of the ASI reflects the strength of the trend. Larger ASI values indicate stronger trends, while smaller values suggest weaker trends or potential trend reversals.
  • Breakouts and Reversals: The ASI can be used to identify price breakouts and reversals. When the ASI crosses above or below a predefined threshold, it may signal a potential breakout or reversal.
  • Divergence: Divergence between the ASI and price can indicate potential trend reversals. If the price reaches a new high or low, but the ASI fails to follow suit, it may suggest that the current trend is losing momentum.

Applying the ASI in Trading

Traders can use the ASI in combination with other technical analysis tools to develop effective trading strategies. Some popular applications of the ASI include:

  1. Trend Confirmation: The ASI can be used alongside moving averages or other trend-following indicators to confirm the prevailing trend direction.
  2. Entry and Exit Signals: Traders can use the ASI to generate entry and exit signals based on breakouts, reversals, or divergence.
  3. Stop Loss Placement: The ASI can help traders determine appropriate stop-loss levels by identifying significant swing highs or lows.


The Accumulative Swing Index (ASI) is a technical analysis tool for identifying and quantifying market trends.

By understanding the ASI’s calculation, interpretation, and application, you can harness its potential to improve your trading strategies.

Combining the ASI with other technical indicators can further enhance its effectiveness and provide a more comprehensive view of market conditions.

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