Files
wickra/bindings/python
kingchenc 880a0e7430 feat: Family 07 Volume - 6 new volume-flow indicators (#45)
* feat(kvo): add Klinger Volume Oscillator

Stephen J. Klinger's trend-aware volume-force MACD. Each bar produces a 'volume force' (vf) signed by the local trend (+1 / -1 / carry) and scaled by the ratio of the current accumulation horizon to its previous trend. KVO = EMA(vf, fast) - EMA(vf, slow), classic (34, 55).

Rust core (Kvo) with 7 unit tests (rejects zero / fast>=slow, accessors, constant series collapses to 0, warmup lands at slow+1, batch == streaming, reset clears state), plus Python (PyKvo + KVO export), Node (KvoNode), and WASM (WasmKvo) bindings. Fuzz target adds Kvo to the candle-input sweep, bench adds the candle-input KVO benchmark, README counter 71 -> 72 + family table row, CHANGELOG [Unreleased].

* feat(volume-oscillator): add Volume Oscillator (VO)

Percent difference between a fast and a slow SMA of the bar volume: 100 * (SMA(vol, fast) - SMA(vol, slow)) / SMA(vol, slow). Default (14, 28). The line stays near zero in stable conditions; positive readings show rising short-term participation, negative readings show waning interest.

Rust core (VolumeOscillator) with 8 unit tests (period validation, accessors, constant volume == 0, zero-volume window defensive branch, two reference values verified algebraically, batch == streaming, reset), plus Python (PyVolumeOscillator + VolumeOscillator export), Node (VolumeOscillatorNode), and WASM (WasmVolumeOscillator) bindings. Fuzz target adds VolumeOscillator to the candle-input sweep, bench adds the volume_oscillator benchmark, README counter 72 -> 73 + family table row, CHANGELOG [Unreleased].

* feat(nvi-pvi): add Negative & Positive Volume Index

Paul Dysart's cumulative volume-flow indices, popularised by Norman Fosback in 'Stock Market Logic'. Both run from a 1000.0 baseline and only update on a specific direction of volume change:

- NVI updates on volume-contraction bars (volume_t < volume_{t-1}), absorbing the percent close change. Tracks the 'smart money' leg per Fosback.
- PVI updates on volume-expansion bars (volume_t > volume_{t-1}). Tracks the 'crowd' leg.

Both expose with_baseline(f64) for custom starting indexes. The NVI/PVI pair is listed as a single line in indicator-ideas/families/07-volume.md and shares the same lifecycle/test/binding surface, so they ship as one commit.

Rust core (Nvi, Pvi) with 9 unit tests each (accessors, baseline seed, volume direction branches, zero-prev-close guard, custom baseline, batch == streaming, reset), plus Python (PyNvi/PyPvi + NVI/PVI exports), Node (NviNode/PviNode), and WASM (WasmNvi/WasmPvi) bindings. Fuzz target adds Nvi+Pvi to the candle-input sweep, bench adds nvi+pvi entries, README counter 73 -> 75 + family table row, CHANGELOG [Unreleased].

* feat(family-07): add Williams A/D, Anchored VWAP, Demand Index, TSV, VZO, Market Facilitation Index

Finishes the volume-flow family with the remaining (new) entries from
indicator-ideas/families/07-volume.md.

Indicators added:

- Williams A/D (`WilliamsAD`): Larry Williams' volume-less cumulative
  accumulation/distribution line. Anchors each bar's contribution to
  the previous close via true-high/true-low (gap-aware).
- Anchored VWAP (`AnchoredVwap`): cumulative VWAP whose accumulation
  starts at a user-chosen anchor bar. Exposes `set_anchor()` (queued
  to the next `update`) for click-to-anchor workflows. Reset clears
  both state and pending-anchor flag.
- Demand Index (`DemandIndex`): James Sibbet's smoothed buying-vs-
  selling pressure, in the streaming-friendly textbook form
  `EMA(volume * close-return * (1 + range/close), period)`.
- Time Segmented Volume (`Tsv`): Don Worden's rolling window-sum of
  `(close_t - close_{t-1}) * volume_t`. Default `period = 18`.
- Volume Zone Oscillator (`Vzo`): Walid Khalil's normalised volume-flow
  oscillator bounded in `[-100, +100]`, defined as
  `100 * EMA(signed_volume) / EMA(volume)`.
- Market Facilitation Index (`MarketFacilitationIndex`): Bill Williams'
  per-bar `(high - low) / volume`. Returns `None` on zero-volume bars.

All six indicators ship with unit tests (`rejects_zero_period` where
applicable, `accessors_and_metadata`, constant-series behaviour,
batch == streaming equivalence, reset semantics, and reference-value
or saturation-extreme tests), Python / Node / WASM bindings, fuzz
coverage in `indicator_update_candle`, a `bench_candle_input` line per
indicator, README + CHANGELOG entries, and Python reference-value
tests in `test_new_indicators.py`.

The README indicator counter advances 75 -> 81.

* test(family-07): cover defensive cold paths + Default impls

- ad_oscillator: exercise `value()` after first emission.
- kvo: cover the `cm == 0.0` zero-OHLC defensive branch.
- nvi / pvi: exercise the Default impls.
2026-05-25 19:15:22 +02:00
..

Wickra

CI codecov crates.io PyPI npm License: PolyForm-NC

Streaming-first technical indicators. Install with pip install wickra — no system dependencies.

Wickra is a multi-language technical-analysis library with a Rust core and bindings for Python, Node.js, and WebAssembly. Every indicator is a state machine that updates in O(1) per new data point, so live trading bots and historical backtests share the exact same implementation.

import numpy as np
import wickra as ta

# Batch: classic TA-Lib-style usage
prices = np.linspace(100, 200, 1000)
rsi = ta.RSI(14)
values = rsi.batch(prices)              # numpy array, NaN during warmup

# Streaming: same indicator, fed tick by tick
rsi = ta.RSI(14)
for price in live_feed:
    value = rsi.update(price)           # O(1) — no recomputation over history
    if value is not None and value > 70:
        print("overbought")

Why Wickra exists

The Python TA ecosystem has plenty of libraries — TA-Lib, pandas-ta, finta, talipp, tulipy — and every one of them shares the same blind spot:

Library Install pain Streaming Multi-language Active
★ Wickra clean yes Python + Node + WASM + Rust yes
TA-Lib (Python) yes (C deps) no no barely
pandas-ta clean no no slow
finta clean no no stale
ta-lib-python yes (C deps) no no barely
talipp clean yes no yes
Tulip Indicators yes (C deps) no partial stale
ooples (C#) clean no C# only yes

Wickra is the only library that combines all of: clean install, streaming, multi-language reach, and active maintenance.

Benchmark: how much faster is "streaming-first"?

The numbers below were measured on a single developer workstation and are not guaranteed to reproduce identically on different hardware — absolute µs values depend on CPU, memory clock and OS scheduler. Read them as relative speedups between libraries on identical input, not as a universal performance contract.

  • Reproduced on: Windows 11 Pro 26200, AMD Ryzen 9 9950X, 64 GB DDR5, Rust 1.92 (release profile, lto = "fat", codegen-units = 1), Python 3.12, Node 20.
  • Reproduce yourself: pip install -e bindings/python[bench] then python -m benchmarks.compare_libraries. The script auto-detects every installed peer library and runs them on the same generated inputs as Wickra. The CI job cross-library-bench runs the same script on every push and uploads the raw report as a build artefact.

Lower µs/op = faster. Wickra wins every batch category outright, and the streaming gap widens linearly with how much history a batch-only library has to recompute on every tick.

Batch — single full pass over a 20 000-bar series

Reading the table: each cell shows that library's runtime, plus how many times slower it is than Wickra in parentheses. marks the winner per row.

Indicator ★ Wickra finta talipp
SMA(20) 95.6 µs ★ 343.5 µs (3.6× slower) 7 640.6 µs (79.9× slower)
EMA(20) 64.6 µs ★ 223.1 µs (3.5× slower) 12 160.9 µs (188.2× slower)
RSI(14) 126.2 µs ★ 1 107.1 µs (8.8× slower) 15 792.2 µs (125.1× slower)
MACD(12, 26, 9) 119.0 µs ★ 531.8 µs (4.5× slower) 49 788.1 µs (418.2× slower)
Bollinger(20, 2.0) 105.3 µs ★ 812.0 µs (7.7× slower) 130 938.3 µs (1 243.7× slower)
ATR(14) 123.5 µs ★ 5 144.8 µs (41.7× slower) 28 816.0 µs (233.4× slower)

Streaming — per-tick latency after seeding with 5 000 historical bars

A batch-only library has to re-run its full indicator over the entire history on every new tick; Wickra updates state in O(1).

Indicator ★ Wickra (per tick) talipp (per tick)
RSI(14) 0.119 µs ★ 1.644 µs (13.8× slower)

TA-Lib and pandas-ta are not included here because both fail to install cleanly on Windows without C build tooling — which is precisely the install pain Wickra was built to remove. The benchmark script auto-detects every peer library it can find and runs them on the same inputs as Wickra; install them in your environment to see those rows light up too.

Run the suite yourself:

pip install -e bindings/python[bench]
python -m benchmarks.compare_libraries

Indicators

71 streaming-first indicators across eight families. Every one passes the batch == streaming equivalence test, reference-value tests, and reset semantics tests.

Family Indicators
Moving Averages SMA, EMA, WMA, DEMA, TEMA, HMA, KAMA, SMMA, TRIMA, ZLEMA, T3, VWMA
Momentum Oscillators RSI (Wilder), Stochastic, CCI, ROC, Williams %R, MFI, Awesome Oscillator, MOM, CMO, TSI, PMO, StochRSI, Ultimate Oscillator
Trend & Directional MACD, ADX (+DI/-DI), Aroon, TRIX, Aroon Oscillator, Vortex, Mass Index, Choppiness Index, Vertical Horizontal Filter
Price Oscillators PPO, DPO, Coppock, Accelerator Oscillator, Balance of Power
Volatility & Bands ATR, Bollinger Bands, Keltner Channels, Donchian Channels, NATR, StdDev, Ulcer Index, Historical Volatility, Bollinger Bandwidth, %B, True Range, Chaikin Volatility
Trailing Stops Parabolic SAR, SuperTrend, Chandelier Exit, Chande Kroll Stop, ATR Trailing Stop
Volume OBV, VWAP (cumulative + rolling), ADL, Volume-Price Trend, Chaikin Money Flow, Chaikin Oscillator, Force Index, Ease of Movement
Price Statistics Typical Price, Median Price, Weighted Close, Linear Regression, Linear Regression Slope, Z-Score, Linear Regression Angle

Adding a new indicator means implementing one trait in Rust; all four bindings inherit it automatically.

Languages

Binding Install Example
Python (PyO3) pip install wickra examples/python/backtest.py
Node.js (napi-rs) npm install wickra examples/node/backtest.js
Browser / WASM npm install wickra-wasm examples/wasm/index.html
Rust cargo add wickra examples/rust/src/bin/backtest.rs

Each binding ships several runnable examples (streaming, backtest, live feed); examples/README.md is the full cross-language index.

The wickra-core crate is unsafe-forbidden, so every binding inherits a memory-safe implementation.

Rust API

use wickra::{Indicator, BatchExt, Chain, Ema, Rsi, Sma};

// Streaming or batch — same trait, same code.
let mut sma = Sma::new(14)?;
let out: Vec<Option<f64>> = sma.batch(&[1.0, 2.0, 3.0, 4.0, 5.0]);

let mut rsi = Rsi::new(14)?;
for price in live_feed {
    if let Some(v) = rsi.update(price) {
        println!("RSI = {v}");
    }
}

// Compose indicators: RSI(7) on top of EMA(14).
let mut chain = Chain::new(Ema::new(14)?, Rsi::new(7)?);
chain.update(price);

Live data sources

wickra-data (separate crate, opt-in) ships:

  • A streaming OHLCV CSV reader.
  • A tick-to-candle aggregator with arbitrary timeframes.
  • A candle resampler for multi-timeframe analysis (1m → 5m → 1h on the fly).
  • A Binance Spot WebSocket kline adapter (feature live-binance).
use wickra::{Indicator, Rsi};
use wickra_data::live::binance::{BinanceKlineStream, Interval};

let mut stream = BinanceKlineStream::connect(&["BTCUSDT".into()], Interval::OneMinute).await?;
let mut rsi = Rsi::new(14)?;
while let Some(event) = stream.next_event().await? {
    if event.is_closed {
        if let Some(v) = rsi.update(event.candle.close) {
            println!("RSI = {v:.2}");
        }
    }
}

A Python live-trading example using the public websockets package lives at examples/python/live_trading.py.

Project layout

wickra/
├── crates/
│   ├── wickra-core/         core engine + all 71 indicators
│   ├── wickra/              top-level facade crate (publishes on crates.io) + benches/
│   └── wickra-data/         CSV reader, tick aggregator, live exchange feeds
├── bindings/
│   ├── python/              PyO3 + maturin (publishes on PyPI)
│   ├── node/                napi-rs (publishes on npm)
│   └── wasm/                wasm-bindgen (browsers, bundlers, Node)
├── examples/                examples/README.md indexes every language
│   ├── data/                real BTCUSDT OHLCV datasets, one per timeframe
│   ├── rust/                Rust workspace member (`wickra-examples`)
│   ├── python/              backtest, live trading, parallel assets, multi-tf
│   ├── node/                streaming, backtest, live trading (load `wickra`)
│   └── wasm/                browser demo for `wickra-wasm`
└── .github/workflows/       CI and release pipelines

Rust benchmarks live in crates/wickra/benches/; runnable Rust examples live in the workspace member crate at examples/rust/. There is no top-level benches/ directory.

Building everything from source

# Rust core + tests
cargo test --workspace
cargo clippy --workspace --all-targets -- -D warnings
cargo bench -p wickra

# Python binding (requires Rust toolchain + maturin)
cd bindings/python
maturin develop --release
pytest

# WASM binding (requires wasm-pack + wasm32-unknown-unknown target)
wasm-pack build bindings/wasm --target web --release --features panic-hook

# Node binding (requires @napi-rs/cli)
cd bindings/node && npm install && npm run build && npm test

Testing

Every layer is covered; run the suites with the commands in Building everything from source.

  • wickra-core: unit tests per indicator — textbook reference values (Wilder RSI, Bollinger Bands, MACD, ATR, Stochastic), batch == streaming equivalence, reset semantics, NaN/Inf handling, and property tests.
  • wickra-data: unit tests for CSV decoding, the tick aggregator, the resampler, and the Binance payload parser.
  • bindings/python: pytest covering smoke checks, streaming/batch equivalence, reference values, lifecycle, input validation, and dict/tuple candle inputs.
  • bindings/node: node --test cases for batch, streaming, and reference values across all indicators.
  • bindings/wasm: wasm-bindgen-test cases for constructors, equivalence, and reference values.

Contributing

Contributions are very welcome — issues, bug reports, ideas, and pull requests all land in the same place: https://github.com/kingchenc/wickra.

A short orientation for first-time contributors:

  • Adding an indicator. Implement the Indicator trait in crates/wickra-core/src/indicators/<name>.rs, wire it into indicators/mod.rs and the crate root, and add reference-value tests, a batch == streaming equivalence test, and (where it makes sense) a proptest. The four bindings inherit your indicator automatically once you expose it in the language wrappers.
  • Fixing a numeric bug. Add a failing test that pins the textbook value first, then fix the math. Property tests in crates/wickra-core catch most regressions; please don't disable them.
  • Improving a binding. Each binding lives under bindings/<lang> with its own tests; please keep the batch == streaming invariant.
  • Style. cargo fmt --all + cargo clippy --workspace --all-targets -- -D warnings are CI gates; running them locally before pushing keeps reviews short.

For larger architectural changes, open an issue first so we can sketch the shape together before you invest the time.

License

Licensed under the PolyForm Noncommercial License 1.0.0. See LICENSE.

In plain English: use it, fork it, modify it, redistribute it, file issues, send pull requests — all welcome. Personal projects, research, education, non-profits, government, hobby trading bots: all fine. The one thing that's not allowed is commercial sale of the software or of services built around it. If you want to use Wickra commercially, get in touch about a license.


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If Wickra saved you time, the cheapest way to say thanks is to the repo.