Candlestick formations

In simple terms

Over centuries, traders have given names to particular shapes of one, two or three candlesticks. These candlestick formations describe what happened in the sessions involved: a battle between buyers and sellers that ended in a particular way.

The descriptions are accurate. The promises attached to them, "a hammer signals a bottom", "an engulfing pattern signals a reversal", are much weaker. This lesson describes the common formations precisely and explains why they should be treated as observations to test.

Single-candle formations

The candlesticks lesson explains bodies and wicks.

Multi-candle formations

Bullish engulfing: a falling candle followed by a rising candle whose body completely covers the previous body. Bearish engulfing is the reverse.

Morning star: a long falling candle, then a small-bodied candle, then a long rising candle that closes well into the first candle's body. Evening star is the reverse.

Harami: a large candle followed by a small one whose body sits inside the first.

Context changes the reading

Traders read formations differently depending on where they appear:

• A hammer after a long fall, at a support zone, is read as more meaningful than one in the middle of a trading range.
• A shooting star after a long rise near resistance is read as more meaningful than one in a quiet market.
• Formations on thin volume, or in thinly traded shares, are considered less meaningful.

These context rules are reasonable descriptions, but they also make formations harder to test, because the definition of "context" can be stretched after the fact.

What the evidence suggests

Academic and practitioner tests of candlestick formations on large samples of shares and markets have generally found that, on their own, most formations have little reliable predictive power for the next few sessions, especially once trading costs are included. Results vary by market and period, and some studies find small effects that disappear in later data.

The gap between the evidence and the popular reputation comes from the same sources discussed in the false signals lesson: memorable examples chosen after the fact, and failures that go unremembered.

Using formations sensibly

1. Describe what the formation shows about the sessions, accurately.
2. Note the context: trend, support or resistance, volume.
3. If you want to use a formation in a trading idea, define it precisely (for example, a hammer's lower wick at least twice its body, closing in the top third of the range) and test it on a sample chosen in advance, as the backtesting lesson explains.
4. Never act on the name alone.

Why it matters

Candlestick formations are among the most widely taught chart tools, often with dramatic names and confident promises. Understanding what they genuinely describe, and how weak the evidence for their predictive power is, protects you from trading on names rather than evidence.

Limitations

Definitions of formations vary between books and charting tools, so the "same" pattern may be identified differently. Results depend on the timeframe, market and period studied. Even where small effects exist, costs can remove them.

Common mistakes

• Treating a formation's name as a prediction.
• Stretching the definition to find the pattern you want.
• Ignoring failed formations when judging how well they work.
• Using formations in thinly traded shares.

Try it yourself

1. Write a precise definition of a hammer, including body size, wick length and where the close sits.
2. Choose five shares in advance and find every hammer by your definition on their daily charts over the last year.
3. Record the price change over the next five sessions after each one.
4. Calculate the average change and the share that rose, and compare with what the formation's reputation suggests.