Short line candle: a quiet day, the TA-Lib rule and the data

A short line is a small candle all round: a body shorter than the recent average and shadows that are short as well. It is the quiet day on a chart, a session where price did not travel far from the open and did not probe far in either direction. Many books call it a short day or simply a small candle.

TA-Lib includes it in its catalog as CDLSHORTLINE, and Finabase shows it as Short Line Candle. Like its opposite, the Long line candle: what TA-Lib’s CDLLONGLINE really measures, it is more a description of a session's size than a pattern with a story. What makes it worth a page is the way the signal is scored. TA-Lib gives the candle +100 if it closed at or above its open and −100 if below, so a stock that drifts up 20 cents on a sleepy day gets a "bullish" label, and one that slips 20 cents gets a "bearish" one. Those labels then flow into Finabase's scanner lists and the Signals-tab gauge.

This page sets out the exact rule, how the short line differs from the doji and the spinning top, two real cases, and the record of 3,587 short lines on 60 large US stocks and ETFs, which contains one of the more surprising results in our candlestick tests.

What a short line looks like

The two illustrations differ only in which end of the small body is the close. To the eye they are the same event: the trend paused for a day. TA-Lib labels the first bullish and the second bearish.

In the traditional literature, small bodies are signs of reduced conviction. Nison discusses small-bodied candles mainly as spinning tops and dojis, and treats them as warnings that a trend is losing momentum, especially after a long run of large candles in one direction. The short line is a narrower case: the body is small and the shadows are short too, so the session was not a tug-of-war with big swings both ways. It was simply quiet.

The exact rules Finabase uses

Finabase uses TA-Lib's CDLSHORTLINE on daily bars:

The output is +100 if the close is at or above the open and −100 if it is below.

Points that are easy to miss

• A doji counts as bullish. TA-Lib treats a close equal to the open as green, so a short line with no body at all scores +100. In our sample that happened 5 times out of 3,587; daily closes rarely match opens to the cent.
• "Short" body means below average, not tiny. In our sample 59% of daily candles had a body below the average of the ten before them. The body test alone passes most days; the shadow test is what trims the count to one day in eight.
• The shadow yardstick is the same one the long line uses. Long line and short line share their shadow rule and have opposite body rules, so the two can never fire on the same bar.
• No context at all. There is no test of the trend, of the previous candle or of where the candle sits in its range.

Short line versus doji and spinning top

Three TA-Lib patterns describe small bodies, and they overlap only partly:

So most short lines are not dojis or spinning tops. They are small, ordinary candles that did not have long wicks.

What a quiet day means

A short line shows a session where neither side moved price far. After a run of long candles, that can mean the side that was driving the trend has paused: buyers are not willing to pay up, sellers are not in a hurry. Some traders read a cluster of short lines after a sharp move as a sign the move is maturing.

The opposite reading is just as common in practice. In an orderly trend, quiet days are where the market digests the prior move before continuing. A string of short lines in a steady uptrend is often called a "rest", and the trend resumes.

Neither reading is about the color. Whether a quiet session closed two cents up or two cents down says very little about who is in control. That is why the color-based labels deserve skepticism.

Confirmation and context

Since the short line makes no directional claim worth confirming, practitioners usually look past it to:

• What came before. A short line after several long candles is a possible pause. A short line in a range of other short lines is just a quiet market.
• The breakout from the quiet day. A close beyond the short line's high or low shows which side stepped back in. In our sample, 732 white short lines (39%) closed above their high the next day and 678 black ones (40%) closed below their low.
• Momentum. A short line while the Relative Strength Index (RSI): how to read and use it is rolling over from above 70 says more than one with momentum still rising.

Two real short lines

Tesla, July 30, 2026. TSLA had dropped 21.0% in ten sessions. On July 30 it opened at $302.70, traded between $301.33 and $310.87 and closed at $308.85. The $6.15 body was under the recent $7.13 average, and the $2.02 and $1.37 shadows were under the recent average shadow, so TA-Lib marked a white short line, +100. The next session closed at $311.21, above the high. Tesla was up 3.5% after five sessions and 10.1% after ten. In hindsight this was a quiet day at a low; nothing in the label said so at the time.

Intel, April 21, 2026. INTC had climbed 25.2% in ten sessions. On April 21 it opened at $67.14 and closed at $66.26, an 88-cent body against a $2.09 average, with shadows of 53 and 62 cents. A pause after a strong run, labeled −100. The next close, $65.27, was below the short line's low, so even the stricter "confirmed" version of the bearish label was met. Intel then went on to gain 27.6% in five sessions and 63.2% in ten. The quiet day was a rest, not a top.

What 3,587 short lines did next

We ran CDLSHORTLINE over two years of daily bars (October 30, 2024 to October 29, 2026) for 60 large US stocks and ETFs, and recorded five-session outcomes in the direction of each candle's color.

Confirmed outcomes are measured from the confirmation close. Returns are raw price changes, not adjusted for the candle's color.

The two rows tell one story when read together:

• After white short lines, prices rose a little more often than usual: 55.3% versus 53.1%.
• After black short lines, prices fell less often than usual: 45.1% versus 46.7%. The bearish label was worse than a coin weighted by the market's own drift.
• Average returns after both colors were positive and similar, +0.48% and +0.55% over five sessions, and +0.84% over ten after black ones.
• Context was evenly split. About 44% of white short lines followed a 10-session decline and 45% of black ones a 10-session rise, close to what you would expect of a candle that ignores trend.

The simplest reading is that quiet days, of either color, tended to be followed by the market's usual upward drift in this period, perhaps slightly more so. The color added nothing useful, and for the black candle it pointed the wrong way.

An educational outline

For learning purposes only.

1. Ignore the color. Treat a short line as "the market paused" and ask what it paused after.
2. Mark the quiet day's range. Its high and low are close together, so a close beyond either one is an early, low-cost sign of which side re-engaged.
3. Use it to judge trend health. Short lines with small pullbacks inside an uptrend are typical of an orderly advance. A sudden long black line after several short lines is a different picture.
4. Illustrative numbers: a short line spans $80.00 to $80.90. A close at $81.20 the next day is above the range; an invalidation under $79.95 makes the risk $1.25 per share, so a $250 budget is 200 shares.

How Finabase shows short lines

• Chart markers. Add the Short Line Candle study (the Tesla link above opens it). Markers appear on roughly one bar in eight, and never on the same bar as a Long Line Candle marker.
• Scanner. By the sign of TA-Lib's output, white short lines are listed as Bullish and black ones as Bearish. A doji-like short line with an unchanged close lands in the Bullish list.
• Signals tab. In the Candlestick gauge, the most recent short line within eight bars casts a Buy (white) or Sell (black) vote. In our sample it voted Buy on 31.3% of days, Sell on 28.8% and was neutral on 39.9%. Since the color carried little information in our test, these votes mostly add noise to the gauge.

Frequently asked questions

What is a short line candle?

A candle with a body shorter than the average of the previous ten bodies and shadows that are each shorter than the recent average shadow. It describes a small, quiet session.

Is a short line bullish or bearish?

TA-Lib labels it by color: +100 green, −100 red. The candle itself is neutral in meaning. In our data both colors were followed by gains more often than declines.

What is the difference between a short line and a doji?

A doji has an open and close that are almost equal, with any shadows. A short line only needs a below-average body, and it also requires short shadows. Fewer than one short line in ten was also a doji in our sample.

Is a short line the same as a spinning top?

No. A spinning top needs shadows longer than its small body; a short line needs shadows shorter than recent average shadows. About 16% of short lines satisfied both.

Summary

The short line is TA-Lib's label for a small, compact candle: below-average body, short shadows, no context. It fires on about one day in eight and is scored bullish or bearish purely by whether it closed above or below its open. In our 3,587-case test that color pointed the right way for white candles by about two points and the wrong way for black ones by about two points, consistent with a rising market drifting up after quiet days. Read it as a pause, judge the pause by what surrounds it, and give its color little weight.