Files
wickra/bindings/wasm
kingchenc 6b8c6a0e7f B5 volatility & bands batch (423 -> 429) (#189)
Adds six **Volatility & Bands** indicators (Part B5 of the expansion roadmap), 423 → 429.

| Indicator | Input → Output | Summary |
|-----------|----------------|---------|
| `EwmaVolatility` | `f64` → `f64` | RiskMetrics exponentially-weighted volatility (λ decay) |
| `Garch11` | `f64` → `f64` | GARCH(1,1) conditional volatility with a long-run-variance anchor |
| `BipowerVariation` | `f64` → `f64` | jump-robust realized bipower variation (π/2 · Σ\|rₜ\|\|rₜ₋₁\|) |
| `VolatilityRatio` | `Candle` → `f64` | Schwager's true range over the EMA of prior true ranges (>2 = wide-ranging day) |
| `VolatilityCone` | `Candle` → `VolatilityConeOutput` | current realized volatility within its min/median/max envelope + percentile |
| `VolatilityOfVolatility` | `f64` → `f64` | sample stddev of a rolling realized-volatility series |

### Notes
- Two B5 roadmap items were dropped as duplicates/by-construction: `RealizedVolatility` already ships (v0.5.4); `Downside Semi-Deviation` is internal to Sortino. `Bipower Variation` confirmed distinct from `JumpIndicator` (a ±1 flag, not a variance measure).
- `VolatilityRatio` implements the widely-charted EMA-of-true-range convention (denominator excludes the current bar so the 2.0 threshold means "twice typical"), distinct from the existing pairwise `variance_ratio`.
- `Garch11` mean-reverts to `ω/(1−β)` on a flat series (does not decay to 0 like EWMA) — pinned by a dedicated test.

### Coverage / verification
- Full core + Python/Node/WASM bindings, fuzz drivers (scalar + candle), registries, CHANGELOG, README + docs counter sync.
- 100% unit-test coverage per indicator (every branch).
- Green locally: `cargo clippy --workspace --all-targets --all-features -D warnings`, core lib (3479) + doc (387), node (504), python (830).

Deep-dive docs for all six are staged for `wickra-docs` and pushed after release (gated).
2026-06-06 22:38:34 +02:00
..

Wickra — WebAssembly

CI codecov npm License: MIT OR Apache-2.0

Streaming-first technical indicators in the browser. npm install wickra-wasm — pure WebAssembly, runs anywhere a modern JS engine does.

Wickra is a multi-language technical-analysis library with a Rust core and bindings for Python, Node.js, and WebAssembly. Every indicator is an O(1) streaming state machine, so live trading dashboards and historical backtests share the exact same implementation. This package is the WebAssembly binding (wasm-bindgen, built for the web target); it exposes 200+ streaming-first indicators across sixteen families.

Install

npm install wickra-wasm

Quick start

The module ships a default init export that loads the .wasm payload; await it once before constructing indicators.

import init, { RSI } from 'wickra-wasm';

await init(); // load the WebAssembly module once

// Streaming: feed prices tick by tick in O(1).
const rsi = new RSI(14);
for (const price of liveFeed) {
  const value = rsi.update(price); // null during warmup
  if (value !== null && value > 70) {
    console.log('overbought');
  }
}

Constructors mirror the other bindings (new SMA(20), new MACD(12, 26, 9), new BollingerBands(20, 2.0), …); update() returns the latest value or null while the indicator is still warming up.

Documentation

The full indicator catalogue, guides, quickstarts, and API reference live in the main repository and documentation site:

Wickra ships four bindings — Python, Node.js, WebAssembly, and Rust — that all expose the same indicators from the shared, unsafe-forbidden Rust core.

Disclaimer

Wickra is an indicator toolkit, not a trading system. The values it computes are deterministic transforms of the input data — they are not financial advice and do not predict the market. Any use in a live trading context is at your own risk. The library is provided as is, without warranty of any kind.

License

Licensed under either of Apache-2.0 or MIT at your option.