A trendline looks simple. Draw a line under price, draw another above price, and the chart suddenly feels easier to understand. For beginners, that can create a dangerous illusion. They start treating the line like a wall, a rule, or a guaranteed support and resistance level.

But markets do not respect lines because traders drew them. Markets move because of liquidity, positioning, orders, catalysts, emotion and risk. That does not make trendlines useless. It makes them misunderstood.

A trendline is not there to predict the future. It is there to help traders organise price action, read behaviour and notice when structure is starting to change.

The beginner mistake

Many new traders use trendlines as automatic entry signals. Price touches an upward trendline, so they buy. Price breaks below it, so th ...