DarkCloudCover — Dark Cloud Cover

A black bar that opens above the previous white bar’s high and closes back below the midpoint of its body: the gap up was sold into. Returns −1.

Signature

DarkCloudCover(lookback, on=<source>)

Argument	Type	Required	Notes
lookback	int Param	Yes	Pinned at 1; the recogniser keeps the previous bar in state. Bounds 1–1.
on=	symbol	No	Source symbol. Defaults to the trade symbol. Reads open, high, low, close.

Formula

Prior bar white; this bar opens above its high and closes below the midpoint of its body but above its open.

Warmup

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

    def execute(self):
        p = DarkCloudCover(1, 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 distribution")
        if p.value < 0 and self.trade.is_long:
            self.sell(self.trade, self.trade.position, reason="Dark cloud cover")

Notes

• The bearish mirror of PiercingLine.