Is a MACD crossover a buy signal?

No. It reports that the gap between two averages changed sign, which by construction happens after price has already moved. In a range it happens constantly and means nothing.

What does the histogram show?

The distance between the MACD line and its signal line. It shrinks before a crossover, which is why traders watch it — it is the earliest part of a late indicator.

What settings should I use?

12/26/9 is the default and what most participants watch, which matters more than the mathematics. Faster settings give earlier signals and more false ones; the trade-off cannot be escaped.

What is MACD?

The distance between two moving averages, plotted as its own line. It measures whether a trend is gaining or losing speed — not whether it is right.

Updated September 4, 2026

Three things, one indicator

The MACD line is the gap between a fast and a slow moving average, usually 12 and 26 periods. When the fast one pulls away, the gap widens; when the trend tires, the gap closes.

The signal line is a moving average of that gap — a smoothed version of itself. The histogram is the distance between the two, which is why it shrinks before they cross: it is the rate of change of a rate of change.

Late by construction, not by accident

Every part of MACD is built from averages of past prices, so it cannot turn before price does. A crossover confirms that something already happened; it never anticipates it.

This is not a flaw to be tuned away. Shortening the periods buys earlier signals and pays for them with false ones — the lag and the reliability are the same dial.

Divergence — the part worth watching

The useful case is disagreement: price makes a higher high while MACD makes a lower one, meaning the new high was reached with less momentum than the previous one.

It says the current leg is thinner than the last, which is a reason to look closer at volume, structure and open interest — not a signal on its own. Divergence can persist for a long time while price keeps going.

Where it misleads

In a range, MACD crosses constantly and every cross looks like a signal. Both averages sit on top of each other, so noise flips the sign again and again.

The honest use is as a trend-quality gauge, not a trigger: it answers "is this move gaining or fading", and that question only makes sense once you have established there is a move at all.

Common questions

Is a MACD crossover a buy signal?: No. It reports that the gap between two averages changed sign, which by construction happens after price has already moved. In a range it happens constantly and means nothing.
What does the histogram show?: The distance between the MACD line and its signal line. It shrinks before a crossover, which is why traders watch it — it is the earliest part of a late indicator.
What settings should I use?: 12/26/9 is the default and what most participants watch, which matters more than the mathematics. Faster settings give earlier signals and more false ones; the trade-off cannot be escaped.