Kagi Chart: Reversal Lines, Yang Signals, and How to Trade

Key Takeaways

• A Kagi line turns yang (thick) when it exceeds the previous up-swing high, and yin (thin) when it falls below the previous down-swing low, these thickness flips are the core buy and sell signals.
• ATR-based reversal of 1–2 ATR is the recommended default; too small a reversal creates constant false flips, too large delays signals until after the move has largely occurred.
• Kagi is built for trending markets; frequent yin-yang flips in sideways conditions are the most common source of losses, a higher-timeframe trend filter screens out the worst environments.
• Volume is absent from Kagi by default; adding a volume panel alongside the chart is essential because a yang flip on shrinking volume is materially weaker than one on expanding volume.

What It Is

Kagi originated in Japan in the 1870s, when the Tokyo Stock Exchange was new and traders needed to see persistent supply and demand without daily noise. The chart consists of long vertical lines connected by short horizontals. The vertical line extends in the current direction as long as price keeps making progress; it reverses only when price moves against the trend by at least the reversal amount.

Line thickness encodes a separate signal. A line is yang (thick) when it climbs above the previous high in the chart and yin (thin) when it falls below the previous low. The thickness flip is the classic Kagi buy or sell signal.

The Intuition

Kagi separates two questions that time-based charts mix together. The first is direction, captured by the line and the small horizontal that connects reversals. The second is structure, captured by the thickness change. A long thin line that suddenly turns thick communicates that the market has just broken a meaningful prior high, irrespective of how many sessions it took.

The trade-off is the same as for any time-independent chart. You lose information about when moves happened, which makes it hard to align Kagi signals with calendar events like earnings dates or FOMC meetings without a parallel time chart.

How It Works

Kagi has one key parameter: the reversal amount. Three styles are common.

Fixed points:    reversal in absolute price (for example, 1 dollar)
Percentage:      reversal as percent of current price (for example, 4 percent)
ATR:             reversal as a multiple of N-period ATR (for example, 1 ATR)

The line construction follows three rules. While price keeps moving in the current direction, extend the existing vertical. When price reverses by at least the reversal amount, draw a short horizontal and start a new vertical in the opposite direction. The line becomes yang (thick) the moment a new vertical surpasses the highest level reached by the prior up-line. It becomes yin (thin) the moment a new vertical drops below the lowest level reached by the prior down-line.

The classical Kagi entry is to buy on a yin-to-yang flip and sell on a yang-to-yin flip. More cautious traders wait for the flip to confirm with a follow-through bar.

Worked Example

Suppose a stock trades with closing prices: 50, 53, 51, 55, 52, 49, 47, 51, 56. You set Kagi reversal at 3 points.

• Start at 50, line moves up to 53.
• 51 is only 2 points down, no reversal yet.
• 55 extends the up line.
• 52 is 3 points down from 55, triggers a horizontal and a new down line.
• Line moves down to 49, then 47. The down vertical now sits below the lowest point of the prior down-line, so the line is yin (thin).
• 51 is 4 points up from 47, reversal triggers a new up line.
• 56 takes the up vertical above the previous up high of 55. Thickness flips to yang, generating the buy signal.

The classic interpretation: the yin-to-yang flip at 56 is the entry, with stop placement just below the prior swing low at 47 or, more aggressively, below the latest reversal at 51.

Common Mistakes

1. Choosing a reversal amount by feel. Too small and the chart prints a flip on every minor wiggle. Too large and signals appear long after the move is over. ATR-based reversal of 1 to 2 ATR is a defensible default that adapts to volatility regime.
2. Confusing horizontals with retracements. The short horizontal segments are not levels of support or resistance; they are connectors. The actionable levels are the previous swing highs and lows that drive the yang and yin labels.
3. Trading every line flip in choppy markets. Kagi is built for trends. Sideways markets produce frequent yin-yang flips that mostly fade. A higher timeframe trend filter, like a 200-day moving average on a daily candlestick chart, helps screen out the worst environments.
4. Mixing closing-price and high-low Kagi. Some platforms use closes only, others scan intraday extremes. The two methods generate different reversal points and different thickness flips. Pick one and stay consistent.
5. Ignoring volume. Kagi shows price structure but contains no volume information by default. A yang signal that prints on shrinking volume is materially weaker than one with a volume expansion. Add volume as a separate panel rather than relying on the line thickness alone.

Frequently Asked Questions

Q: What is a Kagi chart in simple terms? A Kagi chart draws vertical lines that extend as long as price keeps moving in one direction, reversing only when price moves against it by the set reversal amount. When the line breaks above a prior swing high, it turns thick (yang), a buy signal. When it breaks below a prior swing low, it turns thin (yin), a sell signal.

Q: How does a Kagi chart affect investment decisions? The yin-to-yang flip gives a structured trend entry: a trader buys when the line turns yang and places a stop below the prior swing low, keeping risk well-defined. Because thickness changes only at meaningful structural breaks rather than every daily wiggle, Kagi entries tend to catch moves after a decisive shift in supply and demand.

Q: What is a real-world example of a Kagi chart? A stock with a 3-point reversal climbs to 55, reverses to 47 (new yin low), then rallies to 56, one point above the prior up-high of 55. That break of the prior high flips the line from yin to yang, generating the buy signal at 56 with a stop below 47 or the last reversal at 51.

Q: How can investors use Kagi charts practically? Set the reversal amount to 1–2 ATR before analyzing, and add a 200-day moving average on a parallel candlestick chart as a trend filter. One rule: only trade yang signals when price is also above the 200-day MA, most Kagi losses come from trading trend-reversal signals against the broader market direction.

Q: How is a Kagi chart different from a Renko chart? Renko uses uniform-sized bricks in a staircase pattern, with the reversal requiring two brick lengths. Kagi uses variable-length vertical lines with a thickness change that encodes structural breakout information. Renko's signal is the brick color change; Kagi's is the line thickness change at a prior structural level, Kagi carries more context about where the signal is relative to prior price history.

Sources

1. StockCharts ChartSchool. "Kagi Charts." https://chartschool.stockcharts.com/table-of-contents/chart-analysis/chart-types/kagi-charts
2. StockCharts Articles. "Kagi and Renko Charts Come to Town." https://articles.stockcharts.com/article/articles-chartwatchers-2008-04-kagi-and-renko-charts-come-to-town/
3. Corporate Finance Institute. "Kagi Chart." https://corporatefinanceinstitute.com/resources/career-map/sell-side/capital-markets/kagi-chart/
4. Murphy, J. (1999). Technical Analysis of the Financial Markets. New York Institute of Finance. https://archive.org/details/technicalanalysi0000murp

Disclaimer

This article is educational content only and is not financial advice. Nothing here is a recommendation to buy, sell, or hold any security. Consult a licensed advisor before making investment decisions.