Trends/Trendlines and channels

Trendline break and retest

Price closes through a trendline, then comes back to touch the same line from the other side.

Trendlines and channelsBest on 3M, 6M, 1YAlso called break and retest, throwback and pullback

Illustration of the trendline break and retest shape. It is a sketch, not real price data.

What it shows

After a trendline has held for a while, price may close through it. It often then returns to touch the line from the other side. When a broken support line is touched from below, it is called a retest. When a broken resistance line is touched from above, it is also a retest.

Traders pay attention because the line has switched jobs. A floor becomes a ceiling, or the reverse. Our code marks the three steps so you can see them on the chart.

How we find it

The same code that draws it on your chart follows these steps, with the same result every time.

Find a valid trendline with at least 3 touches.
Mark the first bar that closed beyond the line by more than the margin as the break.
After the break, find a bar whose high or low reached back within the tolerance of the line.
Mark that as the retest if price then closes back away from the line.

Starting values: Break margin 1.0% beyond the line; Retest tolerance 1.0% of price; Max bars between break and retest 30. These are proposed and will be tuned on real price data before launch.

How to read it

The gold dot is the first close beyond the line.
The red dot is the retest: price touching the line from the other side.
The dashed part is the line extended after the break.

Status labels you may see

Label	What it means
Intact	No close beyond the line.
Broken	Closed beyond the line, no retest yet.
Retested	Price returned to the line after the break.
Retest failed	Price closed back through the line after the retest.

What cancels it

A close back through the line in the original direction, which cancels the break.

What traders check next

Volume on the break and on the retest.
How many days the retest took.
Whether the retest closed away from the line or just wicked.

Limits

Many breaks never retest.
False breaks look like real ones until later.
The tolerance decides what counts as a retest.

Try it in forecastviz

Open any ticker and choose Trendlines and channels → Trendline break and retest in the left menu.
Switch between 3M, 6M, 1Y to see how the picture changes.
Compare with Uptrend line and Downtrend line on the same chart.

Open on a ticker

Questions

Does every break get a retest?

No. Many do not, and we cannot know in advance which will.

What is the difference between a break and a retest?

The break is the first close through the line. The retest is a later return to the line.