The MACD indicator is a useful tool for analyzing stock market trends. It measures the convergence and divergence of moving averages and can give insight into future price movements. The indicator is made up of three exponential moving averages and when the MACD line is rising, it indicates bullish market conditions. Conversely, a falling MACD line suggests bearish market conditions. The signal line, which is a moving average of the MACD line, can be used to determine entry and exit points. A crossover of the signal and MACD lines can signal a buy or sell opportunity.