Half Trend MACD Indicator MT4 is a trend-following tool that plots a signal line on the chart. When the trend changes, the signal line changes color: blue for uptrends and red for downtrends. You can use it to identify reversals and download it for free from our website. If you’re interested in MACD indicators, there’s also the Impulse MACD for MT4, which combines elements of the MACD with additional features to identify trend changes and momentum shifts.