A trend line is a straight line that connects at least two points and continues to serve as a support or resistance line in the future. By connecting significant lows in an upward trend and significant highs in a downward trend, trend lines provide dynamic resistance. In this context, dynamic resistance denotes that the price of the support or resistance varies over time. During an uptrend, for example, the level of support grows over time. The level of resistance decreases over time in a decline.

A trendline in forex trading is a charting tool that traders use to determine the overall market direction. It is created by linking important price levels, such as consecutive highs or lows, on a trading chart. A rising trendline is formed by connecting higher lows and reflects an upward trend, while a falling trendline joins lower highs and represents a downward trend. Trendlines are useful for spotting trading opportunities, identifying support and resistance zones, and analyzing market behavior. When prices continue to move along the trendline, it confirms that the trend remains strong. On the other hand, if the price breaks the line, it may signal a possible reversal or weakening of the current trend. Forex traders often rely on trendlines together with technical indicators and chart patterns to improve accuracy and make more informed trading decisions in different market conditions.