What is MACD? How it is calculated and read

MACD compares two exponential moving averages of different speeds to show trend strength and turning points.

Updated：2026-11-08

Where the three lines come from

• DIF (fast line): the 12-day EMA minus the 26-day EMA.
• DEA (signal line): the 9-day EMA of DIF.
• OSC (histogram): DIF minus DEA.

An EMA is an exponential moving average: more recent prices weigh more, so it reacts faster than a simple average. The defaults 12, 26 and 9 are the most common settings, and this site lets you change them.

How to read it

• DIF above 0 means the short average is above the long average; below 0 means the opposite. The zero line is where the two averages are equal.
• DIF crossing above DEA, with OSC turning from negative to positive, and the reverse, are called golden cross and death cross. They only describe the relative position of the two lines.
• Longer histogram bars mean the gap between DIF and DEA is widening; shorter bars mean it is narrowing.

Limits

MACD is built from moving averages, so it lags: it describes price changes that already happened and does not predict. In sideways markets DIF and DEA cross often. Use adjusted prices, otherwise ex-dividend gaps distort the values.

Where to see it on this site

On a stock page, open the Technical tab and add MACD. After you change the fast, slow or signal days, the chart redraws immediately.

This article only explains the calculation and how to read a chart. It is not investment advice.