Break of structure and change of character

Two phrases you will hear constantly: break of structure (BOS) and change of character (CHoCH). They come from the same swing-point definition as the trend and they are worth learning as precise events, because most of the confusion around them comes from people using them loosely.

Break of structure: the trend continuing

A break of structure is a close beyond the most recent swing point in the direction of the trend.

• In an uptrend: a close above the most recent swing high. The market has printed a new higher high.
• In a downtrend: a close below the most recent swing low. A new lower low.

BOS confirms the existing trend. It is the moment when the pullback is officially over and the trend has made its next step.

The close at 35.30 is a bullish BOS. It confirms that L3 at 33.20 was a higher low (the trend is intact) and creates a new higher high.

                                   BOS: close above 35.00
                                       |
                                     +---+
                       H2 35.00 -----|---|-------------
                         /\          |   |
                        /  \        +---+
                       /    \      /
                      /      \    /
                     /        \  /
                    /          \/
                   /          L3 33.20 (confirmed as HL by the BOS)

Note the word close. A wick above 35.00 that closes back below is not a BOS; it is a failed break, which is a different event with a different trapped group (Module 5, Lesson 3).

Change of character: the trend failing

A change of character is a close beyond the most recent swing point against the direction of the trend.

• In an uptrend: a close below the most recent higher low.
• In a downtrend: a close above the most recent lower high.

CHoCH is the first evidence that the sequence has broken. The uptrend printed HH, HL, HH, HL, and now a low has printed below the last HL. By the definition in Lesson 1, the uptrend is no longer intact.

                       H3 36.40
                         /\
                        /  \
                       /    \
     L3 33.20 --------/------\------------------
                     /        \
                    /          \
                                +---+
                                |###|   CHoCH: close below 33.20
                                +---+

What CHoCH is and is not

CHoCH does not mean the trend has reversed. It means the uptrend, as defined, has stopped. What comes next is one of:

1. A downtrend, if price now prints a lower high and another lower low.
2. A range, if price bounces and prints roughly equal highs and lows.
3. A resumed uptrend, if the CHoCH turns out to be a deep pullback and price then closes above H3.

The third outcome is common, and traders who treat every CHoCH as a reversal signal get shaken out of good trends. The correct read of a CHoCH is: "the trend is no longer confirmed; I need new evidence before assuming any direction."

Key idea: BOS is a close beyond the last swing with the trend and confirms it. CHoCH is a close beyond the last swing against the trend and removes the confirmation. Neither predicts; both describe.

The trapped groups

BOS traps the sellers who shorted the pullback expecting the swing high to hold. Their stops are just above the swing high, which is why BOS candles are often large: the stops are the fuel.

CHoCH traps the buyers who bought the pullback expecting the higher low to hold. In the example, everyone who bought around 33.20-33.50 as "the trend continuing" is now underwater. The level 33.20 has flipped: it was a higher low (support) and now has trapped longs above it. A rally back to 33.20 will meet their selling. This is the retest that Module 5 builds a setup around.

Sequence: CHoCH, then a lower high, then BOS down

A full reversal from uptrend to downtrend requires three events in order:

1. CHoCH: a close below the last higher low.
2. A lower high: price rallies and fails below the previous high (H3).
3. BOS down: a close below the CHoCH low.

Only after step 3 does the chart meet the downtrend definition (LH and LL). Step 2 is where the retest setup lives. Step 1 alone is a warning.

Traders who short at step 1 are guessing. Traders who wait for step 3 are late but certain of the structure. Most disciplined structure traders act at step 2, when a lower high has formed against a fresh trapped group, with the stop above that lower high.

Minor versus major

Because swings depend on N, so does BOS and CHoCH. A minor CHoCH (N = 3) inside a major uptrend (N = 10) is a pullback. A major CHoCH is a structural event. Always know which one you are looking at. A useful habit is to mark major swings in one colour and minor swings in another, so that a CHoCH on the minor structure is visibly still inside the major.

Where beginners go wrong

• Calling a wick a BOS. Use closes.
• Treating CHoCH as a reversal. It is the removal of a trend, not the start of the opposite one.
• Redefining the swing after the fact so that the CHoCH "didn't count". If your N was 5 and the low broke, it broke.
• Ignoring that CHoCH creates a level. The broken higher low is now resistance with a trapped group; that is more useful than the CHoCH itself.

Try it: On one daily chart with N = 5, find the last three BOS events and the last two CHoCH events. For each CHoCH, write what happened next: a downtrend, a range, or a resumed uptrend. Then mark the broken swing level and check whether price returned to it and what the reaction was.

Recap

• BOS: a close beyond the most recent swing point with the trend. It confirms the trend and traps the counter-trend traders.
• CHoCH: a close beyond the most recent swing point against the trend. It ends the trend's confirmation; it does not start the opposite trend.
• A full reversal requires CHoCH, then a lower high (or higher low), then a BOS in the new direction.
• The swing broken by a CHoCH becomes a level with a trapped group; the retest is where setups form.
• Use closes, know your N, and never redefine the swing after it breaks.