What Is a Trend Line?
A trend line is a straight line drawn on a chart that connects two or more price points and extends into the future. It’s the simplest and most powerful tool in chart analysis.
- Uptrend line — Drawn by connecting two or more higher lows. It acts as dynamic support — the price tends to bounce off the line as the trend continues.
- Downtrend line — Drawn by connecting two or more lower highs. It acts as dynamic resistance — the price tends to reverse at the line during the downtrend.
A valid trend line needs at least two touches, but three or more touches make it significantly more reliable.
How to Draw Trend Lines Correctly
- Identify the trend direction — Is the stock making higher highs and higher lows (uptrend) or lower highs and lower lows (downtrend)?
- Connect the key points — For uptrends, connect the significant lows (not every minor dip). For downtrends, connect the significant highs.
- Use candle bodies, not wicks — Some traders debate this, but using closing prices (candle bodies) tends to produce more reliable trend lines.
- Extend the line forward — Project the trend line into the future to anticipate where the price might find support or resistance next.
Price Channels
A price channel is formed by drawing two parallel trend lines — one connecting the highs and one connecting the lows. The price tends to bounce between these two lines like a ball bouncing between a floor and ceiling.
- Ascending channel — Both lines slope upward. Buy near the lower line, take profits near the upper line.
- Descending channel — Both lines slope downward. Short near the upper line, cover near the lower line.
- Horizontal channel (range) — The stock is trading sideways between support and resistance. Buy at the bottom, sell at the top.
Trend Line Breakouts
When the price breaks through a trend line, it often signals a change in the trend direction. This is called a breakout (if price breaks above a downtrend line or resistance) or a breakdown (if price breaks below an uptrend line or support).
- Volume confirmation — A breakout on high volume is more reliable than one on low volume.
- Retest — After breaking through, the price often comes back to “retest” the trend line. If it holds, the breakout is confirmed.
- False breakouts — Sometimes the price breaks through briefly and then reverses. Wait for a close beyond the line, not just an intraday pierce.
Combining Trend Lines with Indicators
Trend lines work best when combined with technical indicators:
- Trend line + MA150/MA200 — If the price hits an uptrend line at the same level as the MA150, that’s double support. This is a high-confidence buy zone.
- Trend line + RSI — If the price hits an uptrend line and RSI is oversold, the bounce is more likely.
- Trend line + MACD — A bullish MACD crossover at an uptrend line support adds momentum confirmation.
Scanance’s moving average signals essentially identify the same dynamic support/resistance that trend lines show, but calculated objectively without any subjectivity.
Common Trend Line Mistakes
- Forcing a trend line — If you have to stretch or bend the line to make it fit, the trend line isn’t valid.
- Too many trend lines — Drawing dozens of lines creates confusion. Focus on the 1–2 most significant ones.
- Ignoring the break — When a trend line breaks, accept it. Don’t draw a new, flatter line to “save” the trend.
- Using trend lines on short timeframes — Trend lines are most reliable on daily and weekly charts. Avoid drawing them on 5-minute charts.