Guide · Markets
What Is the MACD Indicator? Reading Momentum From Moving Averages
MACD turns the relationship between two moving averages into a single line traders watch for momentum shifts — here's what it actually measures.
MACD (Moving Average Convergence Divergence) is a momentum indicator built from the relationship between two exponential moving averages (EMAs) of price — typically the 12-day and 26-day EMA. Subtracting the longer EMA from the shorter one produces the "MACD line," which oscillates above and below zero as short-term momentum strengthens or weakens relative to the longer-term trend.
A second line, the "signal line," is a 9-day EMA of the MACD line itself — a smoothed version used as a trigger. When the MACD line crosses above the signal line, it's read as a bullish momentum shift; crossing below reads as bearish. The gap between the two lines is often plotted as a histogram, making the size (not just the direction) of the momentum shift visible at a glance.
MACD's real value is in spotting divergence: when price makes a new high but the MACD line fails to make a correspondingly higher high, momentum is weakening even as price still climbs — often an early warning sign before the price trend itself actually turns, though like any single indicator it produces false signals in choppy, range-bound markets and works best combined with other confirmation rather than traded in isolation.
Because MACD is entirely derived from past price (it's a lagging indicator wearing a leading indicator's reputation), understanding exactly what it's built from — not just memorizing "line crosses signal, buy" — is worth doing on Trade2Spike's live charts before trusting a crossover on a real position.