🕯️ Candlestick charts: anatomy, key patterns and what the evidence says

🎯 In 30 seconds: A candlestick shows one period's open, high, low and close. The thick body runs from open to close; the thin wicks reach to the high and low. Green (or hollow) means the close was above the open; red (or filled) means it was below. Patterns like the hammer or the engulfing candle are short descriptions of a fight between buyers and sellers. They only mean something in the right place on the chart, and they work better as a reason to look closer than as a reason to trade. Academic tests of candlestick patterns have produced mixed results, so treat them as a tool to test, not a rule to follow.

Where candlesticks come from

Candlestick charts were developed by rice traders in Japan in the 1700s. Western traders adopted them much later, and today they are the default chart on most trading platforms.

They show exactly the same four numbers as an OHLC bar chart (see Chart basics). The difference is visual: the body makes the open-to-close move jump out, so you can read the mood of a period at a glance.

Anatomy of a candle

• Body: the box between the open and the close. Its height is the net move for the period.
• Upper wick (or upper shadow): the line from the top of the body to the high.
• Lower wick (or lower shadow): the line from the bottom of the body to the low.
• Color: green or hollow when close is above open, red or filled when close is below open. Platforms vary, so check your settings. Some color candles by comparison with the previous close instead.
• Range: high minus low, the total distance traveled.

The candle is not finished until the period ends. A daily candle that looks like a strong green bar at 2:00 p.m. can turn into something very different by the close.

Reading a single candle

Each part of a candle tells a small story about the period.

• Long body, small wicks: one side was in control from open to close. A long green body means buyers pushed all session.
• Long upper wick: buyers pushed the price up, but sellers drove it back down before the close. The high was rejected.
• Long lower wick: sellers pushed the price down, but buyers drove it back up. The low was rejected.
• Small body, wicks both sides: neither side won. That is indecision.

To make this precise instead of a feeling, measure it. Using the up candle in the figure (open $40, high $48, low $38, close $46):

A close in the top 20% of the range means buyers held control into the end of the session. Simple numbers like these are also how you would code a pattern into a screener or backtest.

The patterns traders talk about

Doji. The open and close are equal or very close, so the body is a thin line. It signals indecision. A doji after a long run can show the run is losing energy. A doji in the middle of a choppy range means very little.

Hammer. A small body near the top of the range, a lower wick at least twice the height of the body, and little or no upper wick. It appears after a decline: sellers pushed hard, then buyers took the price back up. The same shape after a rise is called a hanging man and is read as a warning instead.

Shooting star. The hammer upside down: a small body near the bottom, a long upper wick, little or no lower wick, appearing after a rise. Buyers pushed up and failed. The same shape after a decline is called an inverted hammer.

Engulfing. A two-candle pattern. In a bullish engulfing, a red candle is followed by a green candle whose body completely covers the red body. It suggests buyers overwhelmed sellers. A bearish engulfing is the reverse, after a rise.

Morning star and evening star. Three candles. A morning star, after a decline: a long red candle, then a small-bodied candle that gaps lower (the "star"), then a long green candle that closes well into the first candle's body, often past its midpoint. An evening star is the mirror image after a rise.

There are dozens more named patterns. These five cover the main ideas: indecision, rejection of a price, and one side overpowering the other.

Context and confirmation

A pattern is a description of one or a few periods. Whether it means anything depends on where it shows up.

• Trend before it. A hammer only makes sense after a decline. A reversal pattern needs something to reverse. See Trends.
• Location. A hammer at a level where the price turned before carries more weight than one in empty space. See Support and resistance.
• Volume. A reversal candle on heavy volume shows more participants were involved. See Volume.
• Confirmation. Many traders wait for the next candle to agree, for example a close above the hammer's high.

Waiting for confirmation has a cost: you enter at a worse price. In this example the hammer closed at $51.00 and the confirmation day closed at $53.10. The trade-off is fewer false signals in exchange for a later, more expensive entry.

A worked example: turning a pattern into a plan

Say you have a $10,000 account and a rule to risk no more than 1% ($100) on any trade. You see the setup above and decide to buy at the day 7 close.

Notice what the arithmetic tells you. The hammer's long lower wick makes the logical stop far away, so the position must be small. And a 2-to-1 target sits at $66.70, above where the decline started at $60. That target may be unrealistic. A reasonable conclusion is to skip this trade, or to look for a tighter stop with a clear reason behind it.

That is the real use of a candle pattern: it gives you a specific place to define risk. The sizing method comes from Position sizing, and the target logic from Risk/reward and expectancy.

What the evidence says

Candlestick patterns have been tested by academic researchers, and the results disagree.

• Caginalp and Laurent (1998) tested three-day candlestick patterns on daily prices of S&P 500 stocks from 1992 to 1996. They reported statistically significant out-of-sample results and a profit of almost 1% over a two-day holding period.
• Ben Marshall's PhD thesis, published with Martin Young and Lawrence Rose in 2006, tested candlestick strategies on Dow Jones Industrial Average stocks from 1992 to 2002, using a bootstrap method that generates random open, high, low and close prices. The related thesis concludes that candlestick technical analysis "does not have value" and finds no evidence that a trader following it would beat the market.

Two studies on overlapping periods reaching opposite conclusions is a common story in technical analysis. Results depend on the market, the period, the exact pattern definitions, and whether trading costs are included. Patterns that once worked can also stop working once many people trade them.

The practical takeaway: candlestick patterns alone are not a proven edge. They may help you time entries and place stops inside a broader plan. If you want to rely on one, test it on your own data first. Does technical analysis work? explains how to test honestly.

Try it

Pick one pattern, the hammer is a good start. Using daily charts of stocks on your Watchlist, find 20 examples that match your written rule. For each, record the close 5 trading days later and whether a stop just below the low would have been hit. Count how many worked. Then try the same idea in the strategy backtester if it fits one of its rules, or place a few practice trades in the paper portfolio. Log every one in your trading journal.

Sources

• IDEAS/RePEc: Caginalp and Laurent (1998), The predictive power of price patterns, Applied Mathematical Finance
• IDEAS/RePEc: Marshall, Young and Rose (2006), Candlestick technical trading strategies: Can they create value for investors?, Journal of Banking and Finance
• Massey University: Marshall, Candlestick technical trading strategies (PhD thesis, abstract)