Moving average convergence/divergence

What the numbers mean

Twelve and 26 are the fast and slow EMA periods whose difference forms the MACD line; 9 is the EMA of that line plotted as the signal. The histogram is simply the gap between the two. The numbers date from a six-day trading week — 12 and 26 were two and four weeks — and 5/35/5 is a common slower variant for weekly charts.

• 12 — the fast EMA, about two and a half weeks
• 26 — the slow EMA, about five weeks; the numbers come from a six-day trading week
• 9 — the signal line, an EMA of the MACD line itself
• Histogram — MACD line minus signal line; it crosses zero exactly when they cross
• 5, 35, 5 — a slower weekly-chart variant
• 3, 10, 16 — a faster intraday variant

How it is used

Three readings in one: the signal-line crossover as a momentum trigger, the zero-line crossing as confirmation the faster average has actually overtaken the slower, and divergence against price as an early warning that a move is thinning out.

• MACD crossing above its signal line → momentum turning up; the entry trigger
• MACD crossing above zero → the 12 EMA has overtaken the 26; trend confirmation
• Histogram shrinking while price rises → the advance is decelerating
• Price higher high with MACD lower high → bearish divergence

How it relates to everything else

MACD is an EMA crossover system with the answer plotted as a line, so its zero-line cross and a 12/26 EMA crossover are literally the same event. The signal line adds a faster, earlier trigger inside that structure, and the histogram adds a third layer by showing the rate at which the two are converging or diverging. In practice traders read all three in order: histogram first (deceleration), signal cross second (momentum), zero cross last (trend).

• Zero-line cross = a 12/26 EMA crossover, same event, different display
• Signal cross → earliest; zero cross → most confirmed; histogram sits between
• MACD + RSI divergence → the most-used reversal pair on any chart
• MACD + ADX above 25 → filters out the range-bound crossings that cost the most
• Schaff trend cycle is MACD run through a stochastic, so it turns earlier

What to watch for

MACD is unbounded and has no overbought level, so the same reading means different things at different prices. It is a lagging construction by design, and in a range it crosses its signal line every few bars.