HomingPigeon

Two-bar bullish reversal. Two black candles in a decline, the second a small body sitting entirely inside the first body (a same-colour harami). The shrinking range signals selling pressure is fading.

Quick reference

Field	Value
Family	Candlestick Patterns
Input type	Candle
Output type	f64 — +1.0 bullish, 0.0 otherwise (never -1.0)
Output range	{0.0, +1.0}
Default parameters	none — HomingPigeon::new()
Warmup period	2 (first bar always 0.0)
Interpretation	Bullish reversal warning after a decline

Formula

bar1 black (close < open)
bar2 black & its body sits inside bar1's body:  open2 <= open1 && close2 >= close1
bar2 body is smaller than bar1's

Bullish-only (never −1.0). A same-colour harami: like a bullish harami but both candles are black, so it is a softer, warning-grade reversal. See crates/wickra-core/src/indicators/homing_pigeon.rs.

Parameters

None. Constructed with HomingPigeon::new().

Signed ±1 encoding

Single-direction shape: +1.0 bullish, 0.0 no pattern — one feature-matrix dimension.

Inputs / Outputs

use wickra::{Indicator, HomingPigeon, Candle};
// HomingPigeon: Input = Candle, Output = f64
const _: fn(&mut HomingPigeon, Candle) -> Option<f64> = <HomingPigeon as Indicator>::update;

• Always emits a value. Never None; warmup and no-match bars return 0.0.
• Node. update(open, high, low, close) → number; batch(open, high, low, close) → Array<number>.
• Python. update(candle) → float; batch(open, high, low, close) → 1-D numpy.ndarray (0.0 on warmup / no-match).

Warmup

warmup_period() == 2. The first bar returns 0.0 (first_bar_returns_zero, accessors_and_metadata).

Edge cases

• Second bar must be black. A white second bar makes it an ordinary harami, not a homing pigeon (second_bar_white_yields_zero).
• Second body must be inside the first. Otherwise 0.0 (second_body_not_inside_yields_zero).
• Reset. reset() clears the one-bar cache (reset_clears_state).

Examples

Rust

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

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut t = HomingPigeon::new();
    println!("{:?}", t.update(Candle::new(15.0, 15.1, 9.9, 10.0, 1.0, 0)?));  // long black
    println!("{:?}", t.update(Candle::new(14.0, 14.1, 10.9, 11.0, 1.0, 1)?)); // small black, inside
    Ok(())
}

Output:

Some(0.0)
Some(1.0)

The second black body (11, 14) sits inside the first (10, 15) — a homing pigeon. This matches homing_pigeon_is_plus_one.

Python

import numpy as np
import wickra as ta

o = np.array([15.0, 14.0])
h = np.array([15.1, 14.1])
l = np.array([9.9,  10.9])
c = np.array([10.0, 11.0])

print(ta.HomingPigeon().batch(o, h, l, c))  # [0. 1.]

Node

const ta = require('wickra');
const t = new ta.HomingPigeon();
t.update(15, 15.1, 9.9, 10);
console.log(t.update(14, 14.1, 10.9, 11)); // 1

Streaming

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

let mut t = HomingPigeon::new();
let candle_stream: Vec<wickra::Candle> = Vec::new(); // your live OHLCV candle feed
for bar in candle_stream {
    if t.update(bar) == Some(1.0) { /* selling pressure fading — watch for a turn */ }
}

Interpretation

1. Fading downside momentum. The contracted second black body shows sellers losing range — a bullish warning at the foot of a decline.
2. Softer than a harami. Because both candles are black it lacks the colour-flip of a true bullish harami; treat it as a heads-up and confirm.
3. Best at support. Most meaningful after an extended decline.

Common pitfalls

• Expecting a colour flip. Unlike a bullish Harami, the inside bar here is the same colour (black).
• No downtrend context. Only meaningful after a decline.

References

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

See also

• Harami — the colour-flip inside-bar reversal.
• MatchingLow — another soft two-bar bottoming pattern.
• Indicators-Overview — the full taxonomy.