UpDownVolumeRatio

The Up/Down Volume Ratio — total advancing volume divided by total declining volume across a universe. Above one is accumulation, below one is distribution.

Quick reference

Item	Value
Family	Market Breadth
Input type	CrossSection — the per-symbol state of the whole universe
Output type	f64 (a ratio, ≥ 0)
Output range	0.. (unbounded above)
Default parameters	none
Warmup period	1
Interpretation	Volume-flow breadth

Formula

ratio = advancing_volume / max(declining_volume, 1.0)   # per tick

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. When a tick has no declining volume the divisor is floored to 1.0, so the ratio stays finite. Stateless per tick and O(universe size). See crates/wickra-core/src/indicators/up_down_volume_ratio.rs.

Parameters

None. Construct with UpDownVolumeRatio::new().

Parameter	Type	Default	Source
—	—	—	None.

Inputs / Outputs

Indicator<Input = CrossSection, Output = f64>:

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

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

The bindings pass a tick as four equal-length parallel arrays:

• Python: update(change, volume, new_high, new_low); batch(...) returns a 1-D ndarray.
• Node: update(change, volume, newHigh, newLow); batch returns number[].
• WASM: update(change, volume, newHigh, newLow) only; flag arrays are numeric.

Warmup

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

Edge cases

• No declining volume. The divisor is floored to 1.0, so the ratio degrades to the advancing-volume total instead of dividing by zero (test zero_declining_volume_floors_denominator).
• Reset. reset() returns the indicator to not-ready (test reset_clears_state).
• Invalid / empty universe. Rejected at construction by CrossSection::new.

Examples

Rust

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

let mut udv = UpDownVolumeRatio::new();
// advancing volume 150, declining volume 50 -> 3.0.
let tick = CrossSection::new(
    vec![
        Member::new(1.0, 150.0, false, false),
        Member::new(-1.0, 50.0, false, false),
    ],
    0,
)?;
assert_eq!(udv.update(tick), Some(3.0));

Python

import wickra as ta

udv = ta.UpDownVolumeRatio()
print(udv.update([1.0, -1.0], [150.0, 50.0], [False, False], [False, False]))
# 3.0

Node

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

const udv = new UpDownVolumeRatio();
console.log(udv.update([1.0, -1.0], [150, 50], [false, false], [false, false]));
// 3

Streaming

import wickra as ta

udv = ta.UpDownVolumeRatio()
print(udv.update([1.0, -1.0], [150.0, 50.0], [False, False], [False, False]))  # 3.0
print(udv.update([1.0], [100.0], [False], [False]))                            # 100.0 (no down vol)

Interpretation

The Up/Down Volume Ratio measures where the money is going.

1. Above one. More volume in advancing issues — accumulation.
2. Below one. More volume in declining issues — distribution.
3. Thrust signals. Sustained extreme readings (e.g. a 9-to-1 up-volume day) are classic breadth-thrust confirmations of a powerful move.

Common pitfalls

• Floored denominator. When declining volume is zero the ratio equals advancing volume; do not read that single value as an unbounded spike.
• Outliers. A single huge-volume name can dominate the ratio — consider whether to cap or winsorise volumes upstream.
• Universe must be stable. Changing membership makes the totals incomparable.

References

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

See also

• Indicator-Trin — combines this with the advance/decline ratio.
• Indicator-AdVolumeLine — the cumulative net-volume line.
• Indicators-Overview — the full taxonomy.