Harami

Two-bar reversal pattern. The current candle's body sits entirely inside the previous candle's body and points in the opposite direction. Japanese name means "pregnant" — the larger prior bar is the mother containing the smaller current bar.

Quick reference

Item	Value
Family	Candlestick Patterns
Input type	Candle
Output type	f64 — +1.0 bullish, -1.0 bearish, 0.0 otherwise
Output range	{-1.0, 0.0, +1.0}
Default parameters	none — Harami::new()
Warmup period	2
Interpretation	Two-bar reversal with weaker conviction than Engulfing

Formula

prev_body = |prev.close - prev.open|
curr_body = |curr.close - curr.open|

bullish (+1.0): prev red AND curr green
              AND curr.open  >= prev.close
              AND curr.close <= prev.open
              AND curr_body  < prev_body

bearish (-1.0): prev green AND curr red
              AND curr.open  <= prev.close
              AND curr.close >= prev.open
              AND curr_body  < prev_body

Output is 0.0 for the first bar. See crates/wickra-core/src/indicators/harami.rs.

Parameters

None.

Signed ±1 encoding

This pattern already emits the uniform candlestick sign convention shared across the family — +1.0 bullish, −1.0 bearish, 0.0 no pattern — so it drops straight into a machine-learning feature matrix where the bullish and bearish variants of the pattern occupy a single dimension.

Inputs / Outputs

Indicator<Input = Candle, Output = f64>. Same shape as other multi-bar candlestick patterns.

Warmup

warmup_period() == 2. First bar returns 0.0.

Edge cases

• Inverted to Engulfing. Harami is the opposite of Engulfing: current body strictly smaller and inside prior body. Both patterns are reversal patterns but Harami signals indecision rather than full sentiment flip.
• Reset. Clears previous-bar cache.

Examples

Rust

use wickra::{Candle, Harami, Indicator};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let prev = Candle::new(102.0, 103.0, 98.0, 99.0, 1.0, 0)?;  // long red
    let curr = Candle::new(99.5, 100.5, 99.0, 100.0, 1.0, 1)?;  // small green inside
    let mut h = Harami::new();
    h.update(prev);
    println!("{:?}", h.update(curr));  // +1.0
    Ok(())
}

Python

import numpy as np
import wickra as ta

o = np.array([102.0, 99.5])
h = np.array([103.0, 100.5])
l = np.array([ 98.0, 99.0])
c = np.array([ 99.0, 100.0])

ha = ta.Harami()
print(ha.batch(o, h, l, c))

Node

const wickra = require('wickra');
const h = new wickra.Harami();
console.log(h.batch([102, 99.5], [103, 100.5], [98, 99], [99, 100]));

Streaming

use wickra::{Candle, Harami, Indicator};

let mut h = Harami::new();
let candle_stream: Vec<wickra::Candle> = Vec::new(); // your live OHLCV candle feed
for bar in candle_stream {
    if h.update(bar) == Some(1.0) { /* bullish Harami */ }
}

Interpretation

• Indecision after move. Harami signals that the prior bar's momentum has paused — the smaller inside bar shows neither side could push further.
• Weaker than Engulfing. Harami is a soft reversal: signals pause, not necessarily reversal. Often used as a "tighten stops" signal in trend-following systems rather than as a reversal trigger.
• Pair with confirmation. ThreeInside is the confirmed three-bar variant — adds a third bar that closes beyond the prior body.

Common pitfalls

• Treating Harami as a strong signal. Statistical edge is weaker than Engulfing's; many Haramis are continuation pauses.
• Without trend context. Same caveat as all candlestick patterns — context determines value.

References

• Steve Nison, Japanese Candlestick Charting Techniques (1991).

See also

• Engulfing — opposite (large body engulfing small).
• ThreeInside — confirmed Harami.
• Indicators-Overview — full taxonomy.