How to Draw a Trendline: Three Touches, One Line, and What a Break Means
Anyone can connect two points. A trendline that's worth trading has been touched three times and never closed through, and the drawing rules exist to keep you honest about that.
By Pavel Penev, MScFounder, TradeWize · 10+ years trading the marketsThe short answer
In an uptrend, draw the line under the swing lows. In a downtrend, draw it over the swing highs. Start at the first swing of the trend, extend through the next one, and count how many later swings touch it without closing through it. Two touches is a guess. Three is a trendline. A close through it is the trend telling you something changed.
A trendline is a level that slopes. Everything you know about horizontal support and resistance applies to it: it's a zone, not a line; it's worth what its history says; and a close through it means more than a wick through it. The only new part is the geometry, and the geometry is where people go wrong.
This piece gives you the drawing rules, shows a line the engine behind our chart analyzer drew on its own, and finishes with the honest version of what a broken trendline means, which is less than most people think and more than nothing.
Which points to connect
An uptrend is a sequence of higher lows. The trendline is the line those lows sit on. So you connect swing lows, and only swing lows: candles whose low is lower than the few candles either side. Our guide to swing highs and swing lows covers how to spot them. In a downtrend it's the mirror: connect the swing highs.
Start at the beginning of the trend. The first anchor is the low the whole move started from, which is also the lowest point on the chart up to that moment. A line that starts halfway up a trend, ignoring a deeper low before it, isn't the trend's line. It's a line you drew because it fit.
Then extend the line through the next swing low and keep going right. Every later swing low that touches the line without closing through it is a touch. Count them.
Three touches, not two
Any two points make a line. That's geometry, not evidence. A line through two swing lows tells you nothing about whether the market cares about it. The third touch is the first time the line has been tested and held, and it's the first moment the line means anything.
This is the rule the engine uses too. Its trendline detector fits a line through swing lows, requires at least three of them to sit on it within a small tolerance, and rejects any line a later swing has already closed through. Fewer than three, or one breach, and it draws nothing. That strictness is the point: a trendline the tool draws is one that has actually held.
A trendline the tool drew
Here's an uptrend with four higher lows, three of them on one line. The candles are synthetic, built for this article. The line, the touch markers and the read are the engine's, computed the same way our chart analyzer computes them from a screenshot.
What the tool reads on this chart
EXAMPLE broke out of a bull flag 5 days ago. Below $101.66 the break has failed.
- Formation state:
- Broke above $101.66 5 days ago on normal volume. No retest yet.
- Decides above:
- $117.30 (the measured move)
- Decides below:
- $101.66 (the breakout)
A synthetic chart, built for this article and read by the same engine that reads a screenshot on /analyze. No AI wrote this read; it is computed from the candles.
The long diagonal is the trendline the engine fitted through the swing lows, with a marker on each touch. The shaded region is the last pullback, which the engine also reads as a bull flag that has just broken out. The two are the same event: a pullback to the line that held, then a close higher.
Two things in that picture are worth a second look. First, the line starts at the first low of the trend and every touch after it sits on the line without a close below. That's what a valid trendline looks like, and it's why the tool drew it. Second, the engine's headline is about a bull flag, not the trendline. The pullback into the line was shallow and tidy, which is exactly what a flag is, and the bounce off the line was the flag's breakout. One structure, two names. Both are correct, and they agree on the same level.
Learn it by doing
Reading about it is one thing — it clicks when you do it. Learn it hands-on with free, interactive lessons on TradeWize.
Try the free lesson →Wick or close, again
Price will poke through a trendline on a wick and close back above it. That isn't a break. It's the same overshoot you get at horizontal levels, for the same reason: stops sit just past the line and fire as market orders. The engine treats it the same way, as a touch that held, and so should you. A trendline is broken when a candle closes on the wrong side of it.
Draw the zone accordingly. The touches won't sit on the line to the cent. A tolerance of a few percent of the chart's range is what the tool allows, and a line that needs more than that to make its touches fit is being bent to a story.
What a break actually means
Here's the honest version. A close below an uptrend's line means the pace of the trend has changed. It doesn't mean the trend has reversed. The market can close through the line, drift sideways for weeks, and then make a new high on a shallower slope. That's a trend that slowed, not a trend that ended.
The trend has ended when the sequence breaks: a close below the last swing low, not the line. Our piece on break of structure covers that distinction, and it matters, because a lot of people sell the line break and watch the trend continue from a lower angle.
| What closed through | What it means | What to do |
|---|---|---|
| Only the trendline | The trend has slowed. The angle was too steep to hold | Redraw from the same origin through the new low. Watch the last swing low |
| The trendline and the last swing low | The sequence of higher lows has failed | The uptrend is over until a new higher low prints |
| A wick through the line, closed back above | Stops got run. The line held | Nothing. Count it as a touch |
The engine reports both separately: whether the trend is intact, and whether a line or a structure was closed through and how many bars ago.
Redrawing, and when to stop
After a line break that isn't a structure break, redraw. Keep the same origin, the trend's first low, and run the new line through the most recent swing low. You'll get a shallower line, and it needs its own third touch before you trust it. Trends that last a long time go through two or three of these, each one flatter than the last.
Stop redrawing when you're on your fourth line, or when the line is nearly flat. At that point the market isn't trending. It's ranging, and horizontal support and resistance will serve you better than a diagonal you keep adjusting.
How to draw one, step by step
- Find the trend's origin: the swing low the whole rise started from, with no lower low before it on the chart.
- Extend a line from that low through the next swing low.
- Count later swing lows that touch the line without a close below it. Fewer than three, and you have a hypothesis, not a trendline.
- Treat wicks through the line as touches. Treat a close through it as a break of the line, and check the last swing low before calling the trend over.
- After a line break with the structure intact, redraw from the same origin through the newest low, and start counting touches again.
The one-line version
Connect the swing lows from the trend's first low, count three touches before you believe it, and read a close through the line as the trend slowing, not ending, until the last swing low goes too.
How do you draw a trendline correctly?
In an uptrend, connect the swing lows, starting from the low the trend began at and extending through the next swing low. In a downtrend, connect the swing highs. Then count how many later swings touch the line without closing through it. Three touches make it a trendline; two make it a guess.
How many touches does a trendline need?
Three. Two points define any line, so two touches carry no information. The third is the first time the market has tested the line and respected it. The chart analyzer's own detector requires three touches and no close through the line before it draws one.
Should trendlines connect wicks or closes?
Either, as long as you're consistent, and most traders use wicks on daily charts. What matters more is the tolerance: touches won't sit on the line exactly, and a zone a few percent of the chart's range wide is normal. A line that needs a bigger tolerance to fit is being forced.
What happens when a trendline breaks?
A close through the line means the trend has slowed, not necessarily that it has ended. Many trends close below their line, go sideways, and resume at a shallower angle. The trend is over when the last swing low is also closed through, which is a break of structure.
What is the difference between a trendline and support?
A trendline is support that slopes. Both are zones where buyers have stepped in before, both are worth what their history says, and both are broken by a close, not a wick. Support is horizontal and marks a price; a trendline is diagonal and marks a pace.
Can the chart analyzer draw a trendline for me?
Yes. It fits a line through the swing lows of an uptrend or the swing highs of a downtrend, requires three touches and no close through the line, and draws it with a marker on each touch. It also reports whether the line or the structure has been closed through and how long ago. It doesn't tell you to trade the line.
See the trendline on your chart
Upload the screenshot or type the ticker. The chart analyzer fits the trendline through the real swings, marks each touch, and tells you whether the trend still holds. Free, no account, one read a week. It draws the line; the call is yours.