MACD explained

Moving average convergence divergence, line crosses, histograms.

TL;DR

MACD (Moving Average Convergence Divergence) is a trend-following momentum indicator built from moving averages. It produces three signals: line crosses, zero-line crosses, and histogram divergence.

The three components

MACD has a signal line, a MACD line, and a histogram showing the gap between them.

→MACD line: 12-EMA − 26-EMA (the faster minus the slower EMA)
→Signal line: 9-EMA of the MACD line
→Histogram: MACD line − Signal line (visualises momentum changes)

The three signals

Each signal has different reliability characteristics.

→Bullish crossover: MACD line crosses above signal line — momentum turning up
→Bearish crossover: MACD line crosses below signal line — momentum turning down
→Zero-line cross: MACD line crosses zero — the underlying trend itself is changing
→Histogram divergence: histogram peaks/troughs diverge from price — early warning

When MACD works (and when it doesn't)

MACD shines in trending markets and produces many false signals in choppy ranges. Combining MACD with a higher-timeframe trend filter (e.g., 200-day moving average) reduces whipsaws.

Worked example

MACD crossover on the S&P 500 daily

SPX is at $5,400. After a pullback, MACD line crosses up through the signal line below zero.

1MACD line−12 → −8 (rising)
2Signal line−11 (flat)
3CrossMACD crosses above signal — bullish
4HistogramTurns positive for the first time in weeks
5ConfirmationWait for MACD to also cross above zero — that's a regime change, not just a bounce

Takeaway

A crossover below zero is a bounce signal. A crossover above zero is a trend signal — much stronger and more reliable.

Common mistakes

What to avoid

!Trading every crossover without filtering by trend direction or volatility
!Confusing the histogram with the lines — they tell related but different stories
!Using default 12/26/9 on every time frame without testing what suits the instrument
!Ignoring divergence — it's MACD's most underrated signal

Self-check

Test yourself

Q1What does a MACD crossover above the signal line indicate?+

Momentum turning up — bullish signal.

Q2Why is a zero-line cross more meaningful than a signal-line cross?+

It indicates the underlying trend is changing, not just short-term momentum.

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