AdVolumeLine

The Advance/Decline Volume Line — the running cumulative sum of net advancing volume across a universe. The volume-weighted analogue of the A/D Line: a rising line means volume is flowing into advancing issues.

Quick reference

Item	Value
Family	Market Breadth
Input type	CrossSection — the per-symbol state of the whole universe
Output type	f64 (cumulative net-volume line)
Output range	unbounded; may be negative
Default parameters	none
Warmup period	1
Interpretation	Volume-weighted market breadth

Formula

net  = advancing_volume - declining_volume   # per tick
line = line + net                            # cumulative

where advancing_volume is the total volume of symbols with a positive change and declining_volume the total volume of symbols with a negative change (unchanged symbols contribute to neither). The line is a running total, so only its slope and divergences against price matter, not its absolute level. Stateless per tick and O(universe size). See crates/wickra-core/src/indicators/ad_volume_line.rs.

Parameters

None. Construct with AdVolumeLine::new().

Parameter	Type	Default	Source
—	—	—	None.

Inputs / Outputs

Indicator<Input = CrossSection, Output = f64>:

use wickra::{AdVolumeLine, CrossSection, Indicator};

const _: fn(&mut AdVolumeLine, CrossSection) -> Option<f64> =
    <AdVolumeLine as Indicator>::update;

A CrossSection is one tick carrying the universe as a list of Members. The bindings pass a tick as four equal-length parallel arrays:

• Python: update(change, volume, new_high, new_low); batch(...) takes one array group per tick and returns a 1-D ndarray.
• Node: update(change, volume, newHigh, newLow); batch returns number[].
• WASM: update(change, volume, newHigh, newLow) only; the flag arrays are numeric (non-zero is true).

Warmup

warmup_period() == 1; defined from the first tick (tests accessors_and_metadata, first_tick_emits_net_volume).

Edge cases

• Unchanged volume ignored. Volume on symbols with change == 0 counts toward neither bucket (test unchanged_volume_is_ignored).
• Cumulative state. The line accumulates and can go negative (test line_accumulates_across_ticks).
• Reset. reset() restarts the line from zero (test reset_clears_state).
• Invalid / empty universe. Rejected at construction by CrossSection::new; surfaced as ValueError / Error in the bindings.

Examples

Rust

use wickra::{AdVolumeLine, CrossSection, Indicator, Member};

let mut adv = AdVolumeLine::new();
// advancing volume 150, declining volume 50 -> net +100.
let tick = CrossSection::new(
    vec![
        Member::new(1.0, 150.0, false, false),
        Member::new(-1.0, 50.0, false, false),
    ],
    0,
)?;
assert_eq!(adv.update(tick), Some(100.0));

Python

import wickra as ta

adv = ta.AdVolumeLine()
print(adv.update([1.0, -1.0], [150.0, 50.0], [False, False], [False, False]))
# 100.0

Node

const { AdVolumeLine } = require('wickra');

const adv = new AdVolumeLine();
console.log(adv.update([1.0, -1.0], [150, 50], [false, false], [false, false]));
// 100

Streaming

import wickra as ta

adv = ta.AdVolumeLine()
print(adv.update([1.0, -1.0], [150.0, 50.0], [False, False], [False, False]))  # 100.0
print(adv.update([1.0, -1.0], [60.0, 60.0], [False, False], [False, False]))   # 100.0 (net 0)
print(adv.update([1.0], [30.0], [False], [False]))                             # 130.0

Interpretation

The AD Volume Line answers "is volume confirming the breadth move?".

1. Confirmation. A price index and the AD Volume Line rising together mean volume is supporting the advance.
2. Divergence. A rising index with a flat or falling AD Volume Line warns that advancing issues are gaining on light volume — weak participation.
3. Volume vs. issues. Compared to the plain A/D Line (issue counts), the volume line weights each issue by how much actually traded, so a few heavily-traded names can dominate.

Common pitfalls

• Level is arbitrary. Like any cumulative line, only slope and divergences matter, never the absolute level.
• Secular volume growth. Raw net volume grows with overall market activity; for a volume-growth-adjusted reading use CumulativeVolumeIndex.
• Universe must be stable. Changing membership between ticks makes the totals incomparable.

References

• Colby, R. W. (2002). The Encyclopedia of Technical Market Indicators (2nd ed.) — Advance/Decline Volume Line.

See also

• Indicator-CumulativeVolumeIndex — the volume-normalised variant.
• Indicator-AdvanceDecline — the issue-count A/D Line.
• Indicators-Overview — the full taxonomy.