Morning star

A three-bar bullish reversal shape: a down bar, a small bar, then an up bar that closes above the first bar's midpoint.

Morning star checks the last three one-minute bars. The bar two back must close below its open, the bar before the current one must have a body under 30% of that first bar's body, and the current bar must close above its open and above the midpoint of the first bar's open and close. It reads only opens and closes: the highs and lows it is given are never used, and despite the textbook description it checks no gap down and no prior fall.

How to read it

The marker sits on the third bar, the one that completes the shape, not on the small middle bar.
The first bar must close lower than it opened, but nothing checks for a drop before it, so look at the chart for one.
The shape is true on about 2.5% of bars in the sample, so markers are common and one alone says little.

What it outputs

Morning star: Marks the third bar of each bullish three-bar shape: a down bar, a small-bodied bar, then an up bar closing above the first bar's midpoint.

When it fires

Fires on the bar that completes the shape: a down bar, a short pause, then an up bar that closes above the first bar's midpoint. It marks the moment buying lifts price back past the middle of the first bar's body. True on about 2.5% of bars in the sample.

Pitfalls

It is true on about 2.5% of SPY one-minute bars in the sample, roughly 24 a day. That is frequent for a reversal pattern, so one marker is weak evidence on its own.
The code skips the textbook gap-down and large-body checks and does not require a prior fall. Any three bars with that shape qualify, including a doji middle bar.
The highs and lows are passed in but never read, so wick length and bar range do not change the result.