What it is
A moving average is the average closing price over a set number of days. A stock's moving averages are stacked when the short ones sit above the long ones in order. The 8-day sits above the 21-day, the 21 above the 50, and the 50 above the 200. Price itself closes above the 8-day. When every average is rising and none of them cross, they spread apart in a shape traders call a fan. That is where the name comes from.
A stack like that only happens after weeks of higher prices. It is the simplest picture of an uptrend a chart can give you. One good day cannot fake it.
How Breakaway uses it
MA FAN is one of the 14 chart checks and the main trend check. It fires when the 8, 21, 50, and 200-day EMAs are stacked in that order and the close is above the 8-day EMA. An EMA is an exponential moving average, which weights recent days more heavily. Once lit, it stays lit until the close is more than 1.5 percent under the 8-day EMA, or an average falls more than 0.75 percent under the one above it, so a small dip does not flip it. MA FAN also feeds the regime label, which says whether a stock is trending or choppy. A stock with a full stack at a 52-week high, above a rising 200-day average, is called trending up even when ADX is low. The structure of the chart tells you more than a 14-day indicator does.
How to read it
A lit MA FAN chip tells you the trend is already established. It does not tell you a trend is about to start. Look for it alongside a tight-range check such as NR7 or a Bollinger squeeze. That pairing suggests the stock is pausing inside a trend rather than running away from it. A stack that is starting to tighten, with the 8-day dipping toward the 21, is often the moment a swing trader waits for.