Chan Theory Fundamentals: Strokes, Segments, Hubs, Divergence, and Three Types of Buy/Sell Points

Chan Theory is the trading system published by “缠中说禅” on a blog between 2006–2008, covering the complete loop from geometric structure to buy/sell points. Core logic: price movements aren’t random—they have geometric structure. Identifying structure means identifying buy/sell points. Chan Theory is difficult to learn, but once mastered you’ll find that all price movements can be classified, eliminating subjective guesswork.

Core Concept 1: Strokes and Segments

Strokes are Chan Theory’s minimum structural unit:

• Upward stroke: from low point to high point, with at least 1 independent K-line in between (5+ K-lines to constitute a stroke)
• Downward stroke: from high point to low point, also requiring at least 5 K-lines

Segments consist of at least 3 strokes:

• Upward segment: upward stroke + downward stroke + upward stroke (2nd stroke high exceeds 1st stroke high)
• Downward segment: downward stroke + upward stroke + downward stroke (2nd stroke low below 1st stroke low)

Characteristic sequences determine whether a segment has ended: in an upward segment, if the characteristic sequence of downward strokes shows “destruction” (a downward stroke’s low below the prior downward stroke’s low), the segment may end.

Crypto application: BTC daily line rises from $60,000 to $70,000 (upward stroke), retraces to $65,000 (downward stroke), then rises to $75,000 (upward stroke)—constituting an upward segment. The $65,000 retracement doesn’t break the prior low of $60,000; the segment continues.

Core Concept 2: Hubs and Trend Types

A hub is the overlapping price zone formed by at least 3 segments:

• Hub range = [highest of the overlapping lows, lowest of the overlapping highs]
• Z-hub (minimum hub): 3 overlapping strokes suffice

Trend types come in two kinds:

• Consolidation: a trend containing only 1 hub
• Trend: a trend containing 2+ same-direction hubs (rising trend = hubs sequentially ascending; falling trend = hubs sequentially descending)

Hub significance: A hub is the “battlefield” where bulls and bears contest. Price repeatedly struggles within the hub, until one side wins and leaves the hub, forming a trend. Determining whether a hub has been exited determines whether a trend has launched.

Crypto application: BTC oscillates between $65,000–$70,000 for 3 weeks, forming a hub. After breaking $70,000 and retracing without re-entering the hub (holding above $68,000), the rising trend is confirmed. A second hub may form in the $75,000–$80,000 range.

Core Concept 3: Divergence and Buy/Sell Points

Divergence is Chan Theory’s core signal:

• Trend divergence: The last hub’s departure segment has less force than the prior departure segment → trend may reverse
• Consolidation divergence: The final oscillation within the hub shows diminishing force → may exit the hub

Force is measured by MACD area: when the departure segment’s MACD histogram area is smaller than the prior segment, momentum is waning—divergence is established.

Three types of buy/sell points:

• First-type buy point: Divergence point at the last hub of a falling trend (bottom reversal)
• Second-type buy point: After divergence, the low point where the pullback doesn’t re-enter the hub (reversal confirmation)
• Third-type buy point: After breaking the hub, the position where the retracement doesn’t re-enter the hub (trend confirmation)

Sell points mirror correspondingly.

Practical reconstruction: BTC fell from $69,000 to $15,800 (2022), a falling trend with two sequentially descending hubs. The second departure segment’s MACD area was明显 smaller than the first → first-type buy point emerged. After the bounce, the retracement didn’t re-enter the second hub → second-type buy point confirmed. After breaking the new hub, the retracement didn’t re-enter → third-type buy point, trend established.

Common Misconceptions

Misconception 1: Any 3 overlapping strokes form a hub. Chan Theory has strict stroke definitions (5+ K-lines) and segment characteristic sequence judgments. Carelessly drawing strokes and segments produces incorrect hubs and wrong buy/sell points. First use strict rules to draw structure, then determine buy/sell points.

Misconception 2: Divergence = immediate reversal. Divergence indicates momentum waning, not instant reversal. After divergence, price may consolidate (forming a new hub) or move in the opposite direction for a stretch before resuming the original trend. Divergence is a “possible reversal signal,” not a “guaranteed reversal command.”

Summary

Chan Theory’s value lies in providing a rigorous classification framework: price movements are either consolidation or trends, hubs either continue or are exited, and there are only three types of buy/sell points. This eliminates subjective guesswork—what remains is execution. But execution requires stop-losses—Chan Theory’s first-type buy points can also be wrong, and when wrong you must stop out. Stop-loss isn’t a strategic choice; it’s a belief. Without stop-loss faith, any theoretical framework is mere theory.