Heikin-Ashi candles: formula, worked example and how to read them

Heikin-Ashi is a way of drawing candles that smooths out the day-to-day noise. The name is Japanese for "average bar". Each Heikin-Ashi candle is built from averages: its close is the average of the period's four prices, and its open is the midpoint of the previous Heikin-Ashi candle's body. The result is a chart where trends show up as long runs of same-colored candles and pullbacks look smaller than they really were.

That smoothing is the whole point and also the whole cost. A Heikin-Ashi chart no longer shows the prices that actually traded at the open or close, and it reacts to turns a few bars late. This guide gives the formula, works through four real Apple sessions by hand, compares six months of regular and Heikin-Ashi candles, and explains when the trade-off is worth it.

The formula

Three things follow from it.

The close is an average of the whole session. A day that spikes up and closes near its low still has a fairly high HA close, because the high is in the average. That is where the smoothing comes from.

The open carries memory. Each HA open is the midpoint of the previous HA body, so every candle depends on the one before, and that one on the one before it. A gap at the real open does not appear at all: the HA open ignores today's real open entirely.

The color describes the averages, not the session. A Heikin-Ashi candle is green when the HA close is above the HA open. That happens whenever the session's average price is above the midpoint of the previous HA body, which can be true on a day the stock actually fell from its open.

A worked example on real prices

Here are four consecutive AAPL sessions from September 2026, with the Heikin-Ashi values the Finabase chart draws for them. Each row uses the HA open and close from the row above; the HA high and low are worked out in the steps below.

Step by step for September 10:

• HA close = (316.67 + 326.74 + 316.51 + 326.57) ÷ 4 = 1,286.49 ÷ 4 = $321.62.
• HA open = (320.72 + 314.97) ÷ 2 = $317.85, the midpoint of September 9's red HA body.
• HA high = the larger of 326.74, 317.85 and 321.62 = $326.74, the real high.
• HA low = the smaller of 316.51, 317.85 and 321.62 = $316.51, the real low.
• HA close is above HA open, so the candle is green: the first green HA candle after three red ones.

September 11 shows the classic strong-trend candle:

• HA close = (327.45 + 336.22 + 326.30 + 332.27) ÷ 4 = 1,322.24 ÷ 4 = $330.56.
• HA open = (317.85 + 321.62) ÷ 2 = $319.73.
• HA low = the smaller of 326.30, 319.73 and 330.56 = $319.73. The low is the HA open itself, so the green candle has no lower shadow.

September 14 shows how HA can disagree with a regular candle. AAPL opened at $334.79 and closed at $333.08, a red regular candle. But HA close = (334.79 + 335.50 + 331.34 + 333.08) ÷ 4 = $333.68, above the HA open of (319.73 + 330.56) ÷ 2 = $325.15, so the Heikin-Ashi candle stays green. The green run that began on September 10 lasted ten sessions on the HA chart, through September 23.

Regular candles versus Heikin-Ashi on six months of data

The two panels cover the same 120 sessions. A few measurements:

The regular chart changes color every second session on average, which is what daily noise looks like. The Heikin-Ashi chart halves that. Its longest run, 14 green candles at the left edge of the chart, actually began before the window: counted in full it was 21 green candles from April 30 to May 29, 2026, while AAPL's close rose from $271.35 to $312.06, a gain of 15.0%. Over the same stretch the regular candles mixed red and green days.

The HA chart is also visibly more green: 80 green candles against 66. In a rising market, averaging keeps the candle green through small down days, as on September 14.

How to read Heikin-Ashi candles

Traders who use HA tend to read five shapes:

1. Green candles with no lower shadow: a strong uptrend. The HA open was the lowest point of the averaged bar. Trend followers often hold while these continue.
2. Red candles with no upper shadow: a strong downtrend, the mirror image.
3. Green or red candles with shadows on both sides: the trend is still in place but less one-sided.
4. Small bodies with long upper and lower shadows: indecision. These often appear at the end of a run and before a color change.
5. A color change: the averaged price has crossed the previous midpoint. It is the most common HA signal and the one most affected by lag.

Note what is missing: the usual candlestick patterns do not apply. A Hammer candlestick pattern: meaning, rules and reliability or an Engulfing candlestick pattern: bullish and bearish rules and data pattern is defined on real opens and closes. HA candles redraw both, so a "hammer" on an HA chart is not a hammer.

The costs: lag, hidden prices and missing gaps

Lag. Averaging means the chart reacts after the price does. AAPL's close bottomed at $303.42 on August 3, 2026, after a 7.4% fall on July 31. The next day the regular candle was green (+2.0% to $309.38). The HA candles stayed red on August 4 and August 5 and turned green only on August 6, at a close of $312.41, 3.0% above the low. The same lag works at tops: a trend follower who waits for the HA color change gives back part of every move.

Prices that never traded. The HA open and close are calculated values. On September 11 the HA close was $330.56, while AAPL closed at $332.27. If you place a stop or a limit order from an HA chart, use the real price on a regular chart or the quote.

Missing gaps. AAPL gapped down at the open on July 31, 2026, from a $333.43 close to a $304.81 open. A regular chart shows a hole. On the HA chart the July 31 candle opens at $335.19, the midpoint of the previous HA body, and the gap disappears into a long red body. Gap trading: price gap types, gap fills and what the data shows and gap-based signals need regular candles.

Inconsistent indicators. Indicators in Finabase are computed from real prices, whatever chart type you choose. An RSI drawn under an HA chart is the RSI of the real closes. That is usually what you want, but do not expect an indicator to line up with HA candle colors.

When Heikin-Ashi is useful, and when it is not

Many traders keep a regular candlestick chart for decisions and switch to Heikin-Ashi only to answer one question: is the trend still the trend? Heikin-Ashi does much the same job as a short Exponential moving average (EMA): formula and how to use it drawn as candles, and like a moving average it is clear in trends and slow at turns.

How Finabase draws Heikin-Ashi

• Where. Open any chart, such as AAPL six months, and choose Heikin-Ashi from the chart-type menu. It works on every range, from one-day minute bars to the full history.
• Formula. Finabase uses the formula above, seeding the first bar with (open + close) ÷ 2. It draws each wick from the session's real high and low. When the HA body reaches beyond that range, as it often does after a gap, the body covers the wick, so the candle looks the same as one drawn with the textbook HA high and low.
• Colors and saving. HA candles use the chart's up and down colors by HA close versus HA open. Signed in, your choice of chart type is saved per range and shared with the Stock Master apps.
• Indicators. Studies you add are computed from the real prices, whichever chart type is on screen.

Frequently asked questions

Is Heikin-Ashi better than regular candlesticks?

Not better, different. Heikin-Ashi makes trends easier to see and to sit through, which helps trend followers. Regular candles show real prices, gaps and exact session ranges, which every trader needs for orders and patterns. Many people use both.

Why does a Heikin-Ashi candle stay green when the stock fell that day?

Because its color compares the session's average price with the midpoint of the previous Heikin-Ashi candle, not today's close with today's open. In an uptrend that midpoint lags below the price, so a modest down day can still produce a green candle, as AAPL did on September 14, 2026.

Can I use Heikin-Ashi for day trading?

You can draw it on intraday charts, but the lag that helps on daily charts hurts at short horizons, where turns come quickly and every bar of delay costs money. Day traders who use it usually treat it as a trend filter and time entries on regular candles.

Do Heikin-Ashi charts repaint?

No. Once a period closes, its HA candle is fixed. The current candle changes while the period is still open, as any candle does. The only "repainting" is the small seeding effect: a chart that starts on a different date can show slightly different values for its first few bars.

Summary

Heikin-Ashi candles replace each session's open and close with averages: the close is the average of the four prices and the open is the midpoint of the previous HA body. The result halves the number of color changes, as on 120 sessions of AAPL in 2026, and makes runs and strong-trend candles easy to spot. The price is lag, calculated prices that never traded, and hidden gaps. Use Heikin-Ashi to judge whether a trend is intact, and a regular candlestick or bar chart for everything that depends on real prices.