Piercing line pattern: how it forms, TA-Lib rules and track record

The piercing line, also called the piercing pattern, is a bullish two-candle formation found after a decline. The first candle is a long red one. The second opens below the first candle's low, a fresh gap lower, and then rallies to close more than halfway up the red body, without reaching its open. The green candle "pierces" the red one.

It sits on a ladder of similar patterns. A green candle that only gets back to the prior close is a weak counterattack. One that recovers past the middle of the red body is a piercing line. One that closes above the red candle's open has engulfed it. The deeper the recovery, the stronger the message, and the piercing line occupies the middle rung.

This page walks through the shape, the stricter version TA-Lib detects, two real cases from 2025, and the uncomfortable result of our data test, in which piercing lines were followed by declines more often than ordinary days were.

Shape of the piercing line

Four elements make the pattern:

1. A downtrend. Several sessions of lower prices give the pattern something to reverse.
2. A long red first candle, a session of strong selling that closes near its low.
3. A gap down on the open. The second session opens beneath the first candle's low, not just its close. At the open, the decline looks like it is accelerating.
4. A recovery past the midpoint. The green candle closes above the halfway point of the red body but below the red open.

The gap is what gives the pattern its drama. Sellers start the second day in complete control, then lose more than half of the previous day's ground before the close.

The exact rules Finabase uses

Finabase's markers and scanner call TA-Lib's CDLPIERCING. Its test, in plain English:

Where TA-Lib differs from the textbook

Both candles must be long. The classic description only says the first candle is long. TA-Lib also requires the green candle's body to exceed the recent average body. Given the gap below the low and the close above the midpoint, the green body is usually long anyway, but this rule removes a few marginal cases on very volatile stocks.

The midpoint is hard-coded. Some authors accept closes slightly under the midpoint or treat deeper penetration as stronger. TA-Lib simply checks the 50% line. Unlike its bearish mirror, the Dark cloud cover: the pattern and its penetration setting, CDLPIERCING takes no penetration parameter, so Finabase detects it exactly as TA-Lib intends.

There is no trend filter. In our sample 54.4% of piercing lines came after a ten-session decline. The rest formed after sideways or rising stretches, where the reversal idea has less to work with.

The story the two candles tell

The first session ends badly for the bulls: a long red body with a close near the low. Overnight the news or the mood gets worse, and the market opens beneath the entire range of the prior day. Anyone who bought yesterday is deeper in loss, and short sellers are comfortable.

Then demand appears at the lower prices. By the close the market has recovered the gap and more than half of yesterday's decline. The sellers' gap failed, and the bulls recaptured most of the territory they lost.

Most of it, though, is not all. The close below the first candle's open means sellers still hold the upper part of the previous session's body. That is why traders see the piercing line as weaker than the Engulfing candlestick pattern: bullish and bearish rules and data pattern and why practically every source asks for follow-through before treating it as a reversal.

Confirmation: what to wait for

• A close above the green candle's high, the rule in our study.
• A close above the red candle's open, which completes what the piercing line only started and turns the two sessions into the equivalent of a full engulfing.
• Depth of penetration. Closes near the top of the red body are more convincing than closes just past the midpoint.
• Volume. Heavy volume on the green candle suggests real buyers, not just short covering.
• Context that agrees. A bullish divergence on the Relative Strength Index (RSI): how to read and use it, support from an earlier low, or a single-candle signal like the Hammer candlestick pattern: meaning, rules and reliability in the same area.

Two piercing lines from 2025

JPMorgan Chase, April 7, 2025 (worked, without the usual confirmation). JPM had fallen 13.6% in ten sessions during the April 2025 tariff sell-off. On April 4 it closed at $210.28 after opening at $215.31, a long red candle with a low of $208.93. On April 7 it opened at $205.77, below that low, sank to $202.16, then rallied to $214.44, well past the red body's $212.80 midpoint and short of its open. The next session closed at $216.87, under the green candle's $222.05 high, so a strict close-above-the-high rule did not trigger right away. Five sessions later, after the April 9 tariff pause, JPM was 9.5% higher, and after ten it was up 9.9%.

Oracle, November 14, 2025 (failed). Oracle had dropped 15.1% in ten sessions. On November 13 it closed red at $217.57 after opening at $224.99, with a low of $215.22. On November 14 it opened at $210.83, below that low, and closed at $222.85, past the $221.28 midpoint. It looked like a clean piercing line. It never confirmed: the next close was $219.86, and within ten sessions the stock was 9.8% lower, having traded down to $185.63. Three other names in our sample printed a piercing line on the same day, a sign of a market-wide intraday bounce rather than something particular to Oracle.

What the data says

Across 60 large US stocks and ETFs, from October 30, 2024 to October 29, 2026, TA-Lib found 92 piercing lines. We measured each one five and ten sessions later and compared with every day in the sample.

(Two of the 92 were too recent to measure, so the percentages cover 90.)

The raw pattern pointed the wrong way. Fewer than four in ten piercing lines were higher a week later, and the average stock fell 1.66%. In this sample the bounce of the piercing day was, more often than not, followed by renewed selling.

Clustering explains part of it. Piercing lines appear on sharp intraday reversals, and those tend to happen on the same violent days across many stocks. Eight of the 92 fell on December 20, 2024 and seven on March 31, 2025, sessions on which many stocks opened sharply lower and recovered during the day. When the whole market bounces intraday and resumes falling, every one of those signals fails together.

Confirmation flipped the result, on a tiny sample. The 23 confirmed cases were higher five sessions later 60.9% of the time. With 23 observations, that number could easily move by ten points with a different handful of days.

Piercing line versus its neighbors

The last row matters. If the green candle stalls short of the midpoint, the traditional reading is the opposite: a weak bounce inside a downtrend, likely to fail. The midpoint is the dividing line between a reversal attempt and a continuation signal.

An educational outline for a piercing line

How practitioners commonly structure the pattern. It is not a recommendation.

1. Check the decline and the gap. A real downtrend and an open below the prior low.
2. Require follow-through. A close above the piercing candle's high, or above the red candle's open.
3. Place invalidation under the piercing candle's low, the extreme of the failed gap. A new low means sellers regained control.
4. Size from the distance, and look for a target at the start of the red candle or at the next resistance.

How Finabase shows piercing lines

• Charts. Add Piercing Pattern to a chart (the JPM link opens with it on). Expect few markers. Many stocks show one or two in two years, and 11 of our 60 showed none.
• Scanner. Because TA-Lib always returns +100, every piercing line lands on the Bullish list. There is no bearish side to this scan. Its bearish counterpart is a separate pattern with its own detector.
• Signals tab gauge. In the Candlestick gauge on a symbol's Signals tab (JPM for instance) a piercing line in the last eight bars casts one Buy vote among the 61 patterns. On its own it rarely moves the overall verdict.

Frequently asked questions

What is the difference between a piercing line and a bullish engulfing?

How far the green candle recovers. A piercing line closes between the midpoint and the open of the red body. A bullish engulfing closes at or above the red open, covering the whole body.

Does the second candle have to open below the prior low?

In the classic definition and in TA-Lib, yes. An open below the prior close but above the prior low gives a weaker variant that CDLPIERCING will not report.

Is the piercing line reliable?

Not in our data. Unconfirmed piercing lines on 60 large US names were followed by more declines than an average day. The confirmed subset looked better but had only 23 cases.

Why does the piercing pattern not depend on a penetration setting?

TA-Lib hard-codes the 50% midpoint for CDLPIERCING. Its bearish mirror, CDLDARKCLOUDCOVER, takes a penetration parameter instead, and that difference has consequences in Finabase described on the Dark cloud cover: the pattern and its penetration setting page.

Summary

A piercing line is a long red candle followed by a long green candle that gaps below the red low and closes above its midpoint: a failed breakdown that recovers most of the damage. TA-Lib checks both bodies for length, fixes the threshold at 50%, and ignores the prior trend. The pattern is rare, it clusters on volatile market days, and in our two-year sample it was followed by more weakness than strength unless a later close confirmed it. Treat it as a first sign of demand, and wait for the market to prove the demand lasts.