EveningStar — Evening Star

A long white bar, a small gapped-up body, then a black bar closing well into the first: a three-bar top. Returns −1.

Signature

EveningStar(lookback, star_ratio, on=<source>)

Argument	Type	Required	Notes
lookback	int Param	Yes	Pinned at 1; three bars are kept in state. Bounds 1–1.
star_ratio	float Param or literal	Yes	Largest middle body, as a fraction of the first. Default 0.5, bounds 0.1–1.0.
on=	symbol	No	Source symbol. Defaults to the trade symbol. Reads open and close.

Formula

Bar 1 white; bar 2 small and entirely above bar 1’s close; bar 3 black and closing below the midpoint of bar 1’s body.

Warmup

Three bars of state.

Reading the value

p.value
p < 0

Pattern indicators return a flag, not a level: +1 bullish, -1 bearish, 0 absent. They are zero on most bars by design, so treat them as event triggers rather than as something to smooth or cross.

Example

class EveningStarExit(Strategy):
    """Act on the pattern only in the direction of the longer trend."""
    trade = Symbol()
    sizing = FixedCapital()

    def execute(self):
        p = EveningStar(1, 0.5, on=self.trade)
        sma = SMA(50, on=self.trade)
        if p.value == 0 and self.trade.close > sma.value and self.trade.is_flat:
            self.buy(self.trade, reason="No topping pattern")
        if p.value < 0 and self.trade.is_long:
            self.sell(self.trade, self.trade.position, reason="Evening star")

Notes

• The bearish mirror of MorningStar.