Channel walls that flip roles or recapture price

How a price channel is built

A trend channel is formed by pairing a trendline with a second, parallel channel-line so both walls share the same slope. In that pairing the trendline is the boundary drawn along successive lows in an advance or successive highs in a decline and later tested as the channel's primary wall. The channel-line is the parallel counterpart.

Channel lines are drawn along congestion edges rather than through isolated extreme highs and lows. A channel-line is said to reinforce the trendline it parallels. Its validity depends on how many times prices have touched it.

A channel-line marks maximum bullish reach in an uptrend and maximum bearish reach in a downtrend. Wider channels are characterized as stronger trends.

Confirm the corridor

On the illustrated 2005 S&P 500 chart, a descending channel was confirmed by touches in late March, early April, and mid- to late April.

TradersWeek editorial note: those repeated touches are the first test. A corridor that has not been touched often enough is not yet a confirmed price channel.

Judge a break on the close

Once broken, a channel wall can switch from resistance to support or from support to resistance. A later slip back inside the original channel can restore the prior role.

After an early-May upside breakout and a move toward 1180, prices re-entered the old channel during the session but closed back above it. That outside close was treated as a continuation reading, with 1180 cited as the nearby monthly-high reference.

TradersWeek editorial note: this is the close-versus-pierce rule. Discount an intraday return through a broken wall if the session still finishes outside the channel. The role-flip remains the working hypothesis until a close back inside argues for channel-recapture.

Successor-channel or channel-recapture

When the later advance outran the mid-April rising channel, a steeper successor-channel was used. The old upper boundary then acted as support from mid-May to mid-June before the new channel's lower boundary took over.

After prices fell back into the older channel in late June and July, that former upper boundary again acted as resistance, with selling appearing on the session after each test.

TradersWeek editorial note: the mid-May to mid-June stretch is a role-flip of the abandoned wall. The late June and July return is channel-recapture, and the same line went back to resistance.

A break that was not recaptured

On the illustrated US dollar index, prices left the original channel for a steeper one in late May and then broke above that steeper channel without returning to the first corridor. That path contrasts with the S&P 500 example that was recaptured.

TradersWeek editorial note: successor-channel acceptance is not automatic. The dollar sequence stayed outside the first corridor. The S&P 500 sequence did not.