What is ASI?
The Accumulative Swing Index scores every bar against the one before it, using the open, high, low and close of both, and adds those scores into one line in its own pane. Bars that close strongly in the direction of a real swing add a lot; bars that wander without getting anywhere add little. The result is a line that trends with price but is easier to draw clean trendlines and swing points on.
ASI summarises how far and how decisively price has swung. It does not measure volume, it has no fixed scale or overbought and oversold levels, and it does not predict where price will go next.
How to use ASI
- Direction of the line. A rising ASI means bars have mostly closed higher than the previous close, with the open-to-close move agreeing. A falling line means the opposite. The line is drawn green while it is level or rising and red while it is falling.
- Breaks of its own swing points. When ASI moves past its previous swing high or swing low, the swing in price is being read as genuine rather than noise. Agreement with a break in price is the usual way to use it.
- Trendlines on the indicator. Because small, indecisive bars contribute little, trendlines drawn on ASI tend to be cleaner than the same lines on the candles. A break of an ASI trendline is read as a warning that the price trend is weakening.
- Divergence. Price making a new high while ASI does not means the latest push lacked the closes to back it up.
The absolute level of the line is not meaningful. Read its direction and its swing points.
Settings
| Setting | Default | What it changes |
|---|---|---|
| Limit Move Value | 10000 | A scaling constant that every swing score is divided by. Halving it doubles every value and doubling it halves them; the shape of the line does not change. |
Change the Limit Move Value in the indicator settings. Most traders leave it at the default.
Calculation
Each bar is compared with the previous one. C, O, H and L are this bar's close, open, high and low; C1 and O1 are the previous bar's close and open.
K is the larger of the distances from the previous close to this bar's high and low. R is a reference range that depends on which of three distances is largest:
K = max(|H - C1|, |L - C1|)
if |H - C1| is the largest: R = |H - C1| - 0.5 * |L - C1| + 0.25 * |C1 - O1|
if |L - C1| is the largest: R = |L - C1| - 0.5 * |H - C1| + 0.25 * |C1 - O1|
otherwise (|H - L| largest): R = |H - L| + 0.25 * |C1 - O1|
SI = 50 * ((C - C1) + 0.5 * (C - O) + 0.25 * (C1 - O1)) / R * K / limit
ASI = running total of SIThe limit defaults to 10000. It comes from markets that cap how far price may move in a day; crypto has no such cap, so here it acts only as a fixed divisor that sets the scale of the line.
The first loaded bar has no previous bar to compare with, so it has no Swing Index and is left out of the total. The running total starts from zero on the second bar and adds one score per bar from there. Each bar's colour compares its value with the previous bar's: green when equal or higher, red when lower.
Limitations
- The level depends on loaded history. The total starts at the first bar the chart has loaded, so loading more history shifts the whole line up or down. Compare swings and direction, not the number on the axis.
- The scale is not comparable between markets. K is measured in price, so a high-priced market produces much larger values than a low-priced one at the same Limit Move Value.
- It has no volume in it. A swing on thin trading counts the same as a swing on heavy trading.
- Swing points are only clear after the fact. A swing high or low on the line is identified once later bars have moved away from it, so breakout readings come with some delay.
- It is not a strategy. On its own it carries no risk management, sizing or exit.
Frequently asked questions
The Accumulative Swing Index is a running total of Wilder's Swing Index. Each bar gets a score based on how its open, high, low and close relate to the previous bar's, and the scores are added up into a single line that trends with price.
Read its direction and its swing points rather than its value. A rising line backs an uptrend and a falling one a downtrend. When the line breaks a previous swing high or low together with price, the move is being confirmed by decisive closes. When price makes a new extreme and ASI does not, the move is being read as weaker than it looks.
Yes. The indicator declares one input: Limit Move Value, default 10000. It only rescales the line, so changing it alters the numbers on the axis but not the shape, the swings or any crossings of trendlines drawn on it.
Closed bars are not revised by new bars. The current bar's score moves while that candle is live and settles when it closes. Because the line is a running total from the first loaded bar, scrolling back to load older history adds those bars to the total and moves the whole line by the same amount, without changing its shape.
The Swing Index is measured in price and divided by the Limit Move Value, so the size of the numbers follows the price of the market. That is why the axis values differ so much between markets and why only the shape of the line is worth comparing.
Use the Add to chart button at the top of this page. It opens BTC/USDT on Binance in the Altrady Charts terminal with the built-in Accumulative Swing Index already applied. On any other market, open the indicator picker on the chart and choose Accumulative Swing Index from the Momentum group.