The candlestick chart

The bar chart holds everything we need - all four prices - but it is a strain to read. Your eye has to consciously check which tiny tick is on the left and which is on the right just to answer the most basic question: was today up or down? Do that a hundred times across a hundred bars and your attention is gone before you have spotted a single trend.

When you are scanning a chart of three hundred sessions, hunting for the shape of the move, you have no time to squint at ticks. So the question is not about keeping more data - the bar already keeps it all. It is about presentation: how do you make the outcome of each day leap off the screen from across the room, without adding a single new number?

Centuries ago, Japanese rice merchants solved exactly this problem, and their solution is now the default chart on every trading screen in the world. The candlestick uses the same four OHLC prices as the bar - it adds no new maths whatsoever - but it repackages them into two things the human brain reads instantly and effortlessly: colour and mass.

Instead of a thin line with ticks, a candlestick fills in the space between the open and the close as a solid rectangle, and colours it by who won. A green (or hollow) block means the close finished above the open - buyers won. A red (or filled) block means the close finished below the open - sellers won. You no longer decode the day; you simply see it. That single shift from ticks to filled colour is why bars quietly disappeared from most screens and candles took over.

A candlestick has two parts, and the whole language of candles is built from the ratio between them.

• The body is the thick rectangle spanning open to close. Its length shows how much net ground price covered in the period; its colour shows which side won.
• The wicks (also called shadows) are the thin lines poking above and below the body. They reach up to the high and down to the low - marking prices that were touched and then rejected before the close.

Watch a candle physically form during a trading day. The first playbook builds a bullish, buyer-won candle; pay attention to the moment price retreats and leaves a wick behind.

Three shapes make up almost the entire vocabulary, and every named candle is just a different balance of these:

1. The solid block with no wicks - a Marubozu. Total dominance. Price opened at one extreme, ran one direction all day, and closed at the other extreme. A Marubozu is the picture of one side winning uncontested.
2. The long single wick - a rejection. Price reached far in one direction and was shoved all the way back before the close. The wick is the scar left by whoever won the reversal.
3. The cross with almost no body - a doji. The open and close finished level. Buyers pushed, sellers pushed, and by the bell neither had gained an inch - pure indecision.

The single most useful thing to read quickly is the ratio of body to wick. A long body with tiny wicks says one side controlled the whole session - conviction. A tiny body with long wicks on both sides says price travelled far in both directions and settled back in the middle - a fight with no winner. Most real candles sit somewhere between these two poles, and learning to feel where a candle falls on that scale, at a glance, is most of what candle-reading actually is.

Now make the shapes yourself. Move the four prices and watch the body, the wicks, the colour, and the name recompute.

The single most important lesson about candlesticks is not any shape. It is that where a shape forms matters far more than the shape itself.

Below is a run of candles: a steady decline, and then, at the bottom, a single candle with a small body and a long lower wick - a hammer. It says sellers drove price down hard during the day, and buyers dragged it all the way back up by the close.

Here is the honest part. That hammer only earns your attention because it appears after a sustained fall - a place where a failed sell-off is meaningful. Print the identical candle in the calm middle of a strong uptrend and it means almost nothing; price often dips and recovers there every other day. Same shape, different location, entirely different weight. A reader who has memorised candle names but not learned to ask where is this happening? has memorised the alphabet and not learned to read.

A candle's meaning is never fixed by its shape alone; it shifts with three things around it - the trend it sits in, the timeframe, and how far price has already run.

In a trend versus a range. A long lower wick inside a strong uptrend is routine: buyers defend every dip, and the wick is just a dip being bought. The identical wick after a long fall, at a level price has bounced from before, is a genuine event - there, the failed sell-off contradicts the prevailing direction. Same candle, opposite weight, decided entirely by context.

Across timeframes. A doji on a five-minute chart is a moment of lunchtime boredom; a doji on a monthly chart is a whole month of indecision after a long trend - a far heavier thing. The larger the timeframe, the more conviction or exhaustion a single candle represents, because more participants and more time went into forming it.

A note on colour. Green-up and red-down is only a convention, and it is not universal - some traders invert it, and a colour-blind reader may reconfigure it entirely. Never let the colour do your thinking. Read the positions instead: is the close above or below the open, and where does the body sit within the range? Those facts survive any colour scheme; the colour is merely a shortcut for the eye.

The through-line of this whole part is now visible. The chart type changes how the same four prices are drawn, but never what they are. Reading well is reading those four numbers in their setting - not memorising the names of shapes.

A candlestick inherits every blind spot of the bar, because it is the same four numbers wearing better clothes.

It cannot tell you the order the high and low arrived in. A candle with a long upper and a long lower wick could have gone high-then-low or low-then-high; the daily candle cannot say which. To recover the sequence you must drop to a lower timeframe.

It cannot make a single candle into a signal. The market is full of people selling the opposite claim - that a hammer means buy, that an engulfing means sell - and it is worth being blunt about why that is wrong. A candle is a record of one finished session. A textbook shape shifts the odds a little at best; it never promises the next move. Bought as a certainty, it is a coin flip you have paid a course fee to misunderstand.

And it cannot, on its own, be a complete method. There is no candle, and no combination of candles, that removes the need to read context, risk and the business. The shape is one input among several, valuable only when it is weighed against where it forms and what else is true.

The great trap is treating candles like magic runes. A fin-influencer shows five charts where a hammer nailed the low and sells a course promising you must buy the next one you see. But those five were chosen after the fact; the hammers that failed never made the slide.

Two honest readers can look at the very same hammer and disagree - and both can be reasoning well.

The repair, once more, is to fix your exit before you act. If the very next session closes back below the hammer's low on strong volume, the 'reversal' read is dead. State that condition in advance, or you were never reading the candle - you were hoping at it, and dressing the hope up as analysis.

The candlestick is the chart you will use for almost all of your reading. But modern software adds a puzzling variant: a candle coloured red yet drawn hollow, or green yet solid. How can a down-day be empty? We clear up the hollow candle next.