Morning Star / Evening Star

Three-bar reversal pattern. A long candle, then a small "star" (small-body bar of either colour) whose body gaps away from the first bar's body, then a long candle in the opposite direction that closes at least 30% of the way into the first bar's body. Morning Star is bullish (long red → star → long green); Evening Star is the bearish mirror. Among the strongest classical candlestick reversal patterns.

Quick reference

Item	Value
Family	Candlestick Patterns
Input type	Candle
Output type	f64 — +1.0 Morning, -1.0 Evening, 0.0 otherwise
Output range	{-1.0, 0.0, +1.0}
Default parameters	none — MorningEveningStar::new()
Warmup period	3
Interpretation	Strong three-bar reversal signal

Formula

Morning Star (+1.0):

Bar 1: long red candle
Bar 2: small-body candle ("star")  — colour does not matter,
       body gaps below Bar 1's body: max(open2, close2) < close1
Bar 3: long green candle, close3 > close1 + 0.3 · body1
       (body1 = |close1 − open1|)

"long" enforced by: outer_body >= 2 · star_body

Evening Star (-1.0): mirror — long green, a small star whose body gaps above it (min(open2, close2) > close1), long red closing at least 30% of the way down into Bar 1's body (close3 < close1 − 0.3 · body1). The star's body gap is the defining feature (Nison; TA-Lib CDLMORNINGSTAR / CDLEVENINGSTAR). The 30% penetration is TA-Lib's default penetration = 0.3; earlier releases required Bar 3 to pass Bar 1's midpoint (50%). See crates/wickra-core/src/indicators/morning_evening_star.rs.

TA-Lib parity. On the TA-Lib reference pattern series the signals are identical to CDLMORNINGSTAR / CDLEVENINGSTAR with penetration = 0.3 (+1 / −1 here, +100 / −100 there). The one structural difference: TA-Lib sizes bodies against a rolling average of the previous bars ("candle settings"), while Wickra sizes them against the pattern's own bars (the outer bodies must be at least twice the star's body).

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>. Python: (n,) array with NaN for the first 2 bars. Node: same.

Warmup

warmup_period() == 3. First two bars return None (first_two_bars_return_zero); the pattern emits on bar 3 of the three-bar sequence.

Edge cases

• Star colour is arbitrary. The middle "star" bar can be red, green, or doji — the pattern only requires it to be smaller than the outer bars (at least 2:1 ratio).
• Star body must gap. For Morning the star's whole body must sit below Bar 1's close (max(open2, close2) < close1); for Evening above it (min(open2, close2) > close1). A star whose body overlaps Bar 1's body yields 0.0. Only wicks may overlap, and no gap is required between Bar 2 and Bar 3.
• 30% penetration, strict. Bar 3 must close more than 30% of Bar 1's body into it — above close1 + 0.3 · body1 for Morning, below close1 − 0.3 · body1 for Evening. A close exactly on the threshold yields 0.0. The penetration requirement is what separates a true Star pattern from a noisy 3-bar pause.
• Reset. Clears the two-bar history.

Examples

Rust

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

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Morning Star
    let b1 = Candle::new(12.0, 12.2, 9.5, 10.0, 1.0, 0)?;  // long red
    let b2 = Candle::new(9.9, 10.1, 9.7, 9.95, 1.0, 1)?;    // doji-ish star, body below 10.0
    let b3 = Candle::new(10.0, 12.0, 9.9, 10.8, 1.0, 2)?;   // long green, closes 40% into bar 1's body
    let mut s = MorningEveningStar::new();
    s.update(b1); s.update(b2);
    println!("{:?}", s.update(b3));  // Some(1.0)
    Ok(())
}

Python

import numpy as np
import wickra as ta

o = np.array([12.0, 9.9, 10.0])
h = np.array([12.2, 10.1, 12.0])
l = np.array([ 9.5, 9.7, 9.9])
c = np.array([10.0, 9.95, 10.8])

s = ta.MorningEveningStar()
print(s.batch(o, h, l, c))  # array('d', [nan, nan, 1.0])

Node

const wickra = require('wickra');
const s = new wickra.MorningEveningStar();
console.log(s.batch([12, 9.9, 10], [12.2, 10.1, 12], [9.5, 9.7, 9.9], [10, 9.95, 10.8]));
// [ NaN, NaN, 1 ]

Bar 1's body is 12.0 − 10.0 = 2.0, so Bar 3 must close above 10.0 + 0.3 · 2.0 = 10.6. The close of 10.8 passes (it would have failed the old midpoint rule at 11.0); a close of 10.5 returns 0.0.

Streaming

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

let mut s = MorningEveningStar::new();
let candle_stream: Vec<wickra::Candle> = Vec::new(); // your live OHLCV candle feed
for bar in candle_stream {
    match s.update(bar) {
        Some(v) if v > 0.0 => { /* Morning Star */ }
        Some(v) if v < 0.0 => { /* Evening Star */ }
        _ => {}
    }
}

Interpretation

• Strong reversal. Among the highest-conviction classical candlestick patterns. The star bar in the middle marks capitulation; the third bar confirms the new direction.
• Best at extremes. Morning Star at a key support level is particularly powerful; the same pattern in the middle of a range is just noise.
• Gap variant. Classical Morning Star has gaps between Bars 1-2 and 2-3. Wickra follows Nison and TA-Lib in requiring the star's body to gap away from Bar 1's body (wicks may overlap), but does not require a gap between Bars 2 and 3.

Common pitfalls

• Confused with Doji-only middle bar. The middle bar must be small but not strictly a Doji. Many Stars have a small green or red middle bar.
• Star overlapping Bar 1's body. A small bar that opens or closes inside Bar 1's body is not a star here, however small its body.
• Penetration threshold. Bar 3 only needs to close 30% of the way into Bar 1's body, not past its midpoint and not past Bar 1's open. Code that assumed the older 50% (midpoint) rule will see more signals.

References

• Steve Nison, Japanese Candlestick Charting Techniques (1991) — Morning / Evening Star definitions.
• TA-Lib CDLMORNINGSTAR / CDLEVENINGSTAR.

See also

• Doji — common shape of the middle "star" bar.
• Engulfing — two-bar reversal sibling.
• ThreeInside / ThreeOutside — other three-bar confirmations.
• Indicators-Overview — full taxonomy.