wickra/docs/wiki/indicators/volume/Indicator-Adl.md

ADL

Accumulation/Distribution Line — a cumulative volume-flow line that weights each bar's volume by where its close fell within the range.

Quick reference

Field	Value
Family	Volume
Sub-category	Cumulative
Input type	Candle (uses high, low, close, volume)
Output type	f64
Output range	unbounded (drifts with cumulative volume)
Default parameters	none (no parameters)
Warmup period	1
Interpretation	Running buying/selling pressure; slope and divergence matter.

Formula

MFM_t = ((close − low) − (high − close)) / (high − low)   (money-flow multiplier, −1..+1)
MFV_t = MFM_t · volume_t                                  (money-flow volume)
ADL_t = ADL_{t−1} + MFV_t

The money-flow multiplier asks where in the bar's range did price close? A close on the high gives +1 (full accumulation), on the low −1 (full distribution), in the middle 0. Scaling by volume and running the cumulative total gives a line whose slope reflects sustained buying or selling pressure. A bar with high == low carries no positional information and contributes 0.

Parameters

ADL takes no parameters — Adl::new() in Rust, wickra.ADL() in Python, new ta.ADL() in Node.

Inputs / Outputs

From crates/wickra-core/src/indicators/adl.rs:

impl Indicator for Adl {
    type Input = Candle;
    type Output = f64;
    // update(&mut self, input: Candle) -> Option<f64>
}

ADL is a candle-input indicator: it reads high, low, close and volume. In Python the streaming update accepts a 6-tuple or a dict; the batch helper takes high, low, close, volume numpy arrays. Node and WASM expose update(high, low, close, volume) and the matching batch.

Warmup

Adl::new().warmup_period() == 1. ADL is cumulative — it emits a value from the very first candle.

Edge cases

• Zero-range bar. A bar with high == low contributes 0 to the line (zero_range_bar_contributes_nothing pins this).
• Close at the high. Every bar closing on its high has MFM = +1, so ADL grows by exactly volume each bar (close_at_high_accumulates_full_volume pins this).
• Candle validation. Candle::new rejects invalid bars upstream.
• Reset. adl.reset() returns the running total to 0.

Examples

Rust

use wickra::{BatchExt, Candle, Indicator, Adl};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut adl = Adl::new();
    let out = adl.batch(&[
        Candle::new(8.0, 10.0, 8.0, 10.0, 100.0, 0)?,  // close at high
        Candle::new(10.0, 12.0, 8.0, 9.0, 200.0, 1)?,
    ]);
    println!("{:?}", out);
    Ok(())
}

Output:

[Some(100.0), Some(0.0)]

Bar 1 closes at its high (MFM = +1), adding +100. Bar 2 has MFM = ((9−8)−(12−9))/4 = −0.5, adding −100, so the line returns to 0. This matches the reference_values test in crates/wickra-core/src/indicators/adl.rs.

Python

import numpy as np
import wickra as ta

adl = ta.ADL()
high = np.array([10.0, 12.0])
low = np.array([8.0, 8.0])
close = np.array([10.0, 9.0])
volume = np.array([100.0, 200.0])
print(adl.batch(high, low, close, volume))

Output:

[100.   0.]

Node

const ta = require('wickra');
const adl = new ta.ADL();
console.log(adl.batch([10, 12], [8, 8], [10, 9], [100, 200]));

Output:

[ 100, 0 ]

Interpretation

Adl is read by slope and by divergence, never by absolute level (the total drifts arbitrarily with cumulative volume). A rising ADL confirms that an up-move is backed by accumulation; a falling ADL while price rises is a bearish divergence — the rally is not being bought into. ChaikinOscillator is the standard way to turn the ADL into a bounded, tradeable oscillator.

Common pitfalls

• Reading the absolute value. Only the slope and divergences are meaningful; the level depends on where you started the stream.
• Feeding it scalar prices. It needs the full OHLCV bar.

References

Marc Chaikin's Accumulation/Distribution Line; the money-flow-multiplier formulation here matches the standard definition (StockCharts, TA-Lib's AD).

See also

• Indicator-Obv.md — cumulative signed volume.
• Indicator-ChaikinOscillator.md — an oscillator built on the ADL.
• Indicators-Overview.md — the full taxonomy.