How it works
The rule is mechanical and published in full, so you can check any alert yourself.
The definition
Bullish
On a given trading day t, both must be true:
- The 21-day EMA crosses above the 55-day EMA on day
t: it was at or below yesterday and is above today. - The 21-day EMA crossed above the 233-day EMA on any of the last 10 trading days, including day
t.
Bearish
The mirror image: 21 crosses below 55 today, and 21 crossed below 233 within the last 10 trading days.
Details
- EMAs use daily closing prices, smoothing factor 2 / (N + 1), each seeded with the simple average of its first N closes.
- A stock needs at least 233 trading days of history before it can signal, so recent IPOs are skipped.
- The scan runs once per trading day after the US market closes, on end-of-day data.
- Signals are rare, because both crosses must line up inside a short window. Some days have none, and no email is sent.
What it is not
A crossover is a description of past prices. It is not a forecast, and many signals fail. Use it as a prompt to look, not a reason to trade.