MACDMoving Average Convergence Divergence

What is MACD?

MACD was invented by Gerald Appel in the late 1970s. It plots three components: the MACD line (12 EMA minus 26 EMA), the signal line (9 EMA of the MACD line), and a histogram showing the difference between the two.

Because MACD subtracts a slower EMA from a faster one, it produces a value that oscillates around zero. Above zero means the fast EMA is above the slow EMA — a bullish bias. Below zero is bearish bias. The signal-line crossovers add timing specificity within those biases.

Category

Trend / momentum

Default settings

12, 26, 9

Signal range

Unbounded (centered on 0)

Introduced by

Gerald Appel, late 1970s

How MACD works

Three calculations make up the indicator:

MACD line = EMA(12) - EMA(26) Signal line = EMA(9) of MACD line Histogram = MACD line - Signal line

When the MACD line crosses above the signal line, the histogram turns positive — a bullish signal. When it crosses below, the histogram turns negative — a bearish signal. The histogram itself shows the strength: rising bars mean accelerating momentum; falling bars mean decelerating momentum, often preceding a reversal.

How to use MACD

Three practical setups, ranked by reliability.

1. Divergence at structure: Price makes a higher high; MACD histogram makes a lower high. Most reliable when it aligns with horizontal resistance or a key trendline. Same setup mirrored at support for longs.

2. Zero-line crosses as trend filter: Only take longs when MACD is above zero, only shorts when it is below. Cuts out roughly half of choppy-range setups.

3. Signal-line crosses: Buy when MACD crosses above the signal line in an uptrend. Sell when it crosses below in a downtrend. Avoid using these crosses in ranges — they generate too many false signals.

Avoid the rookie mistake of trading every signal-line crossover regardless of context. The MACD is a trend tool. It generates noise in choppy markets.

Want more practical context? Look up unfamiliar terms in the forex glossary, or see how indicators stack on real charts in the trading blog.

MACD FAQ