Definition
MACD is a momentum indicator derived from the difference between faster and slower exponential moving averages, often compared with a signal line.
In market context
Analysts interpret line crossovers, movement around zero, and divergence from price as descriptions of changing momentum. Settings determine sensitivity, and signals can arrive after a large part of a move because all components use historical prices. MACD can produce frequent whipsaws in range-bound markets, so it should not be treated as a standalone forecast or guaranteed timing tool for decisions.
Source
Use the primary source for fuller regulatory or market context.
