Page "MACD" Paragraph 4

Since the MACD is based on moving averages, it is inherently a lagging indicator.

However, in this regard the MACD does not lag as much as a basic moving average crossing indicator, since the signal cross can be anticipated by noting the convergence far in advance of the actual crossing.

As a metric of price trends, the MACD is less useful for stocks that are not trending ( trading in a range ) or are trading with erratic price action.