Shark pattern — Carney's O-X-A-B-C harmonic reversal

The Shark is one of the youngest harmonic formations — Scott Carney only described it in 2011, after the second volume of his harmonic trading series had already appeared. What sets it apart is its unusual labelling, with points marked O-X-A-B-C instead of the classical X-A-B-C-D, and its deep, overshooting Fibonacci extensions. In practice the Shark often serves as the prelude to another Carney formation, the 5-0 pattern. Below I explain how to spot it, where the entry sits, and how to place a sensible stop and targets.

What the Shark pattern is and where it came from

The Shark is a five-point reversal formation that Scott Carney added to the harmonic family as its newest member. The name comes not from any mathematical formula but from the shape on the chart — the sharp, asymmetric thrust resembles a shark fin. Carney deliberately broke his own naming convention here: instead of the traditional X-A-B-C-D, the points are labelled O-X-A-B-C. That is not cosmetic; it signals that the measurement logic differs from the Gartley or the Bat.

It is best to treat this figure as part of a larger whole. If you are just starting out, work through the basics of trading harmonic patterns first — they all rest on the same principle of Fibonacci relationships between successive legs, and without that foundation the Shark measurements are just guesswork.

The O-X-A-B-C structure and Fibonacci levels

„Harmonic patterns identify price relationships using Fibonacci ratio analysis to precisely define market turning points." — Scott M. Carney, Harmonic Trading, Volume Two, Pearson, 2010

The formation consists of five points joined by four legs: O-X, X-A, A-B and B-C. Point O is where the whole structure begins, and the O-X leg marks the first clear move. The X-A leg then pulls back against it, the A-B leg extends between 1.13 and 1.618 of the X-A leg, and then comes the decisive, excessive B-C leg. That leg gives the pattern its character: the market overshoots and reaches an extension of 1.13 to 1.618 of the A-B leg.

The most important condition, however, is the completion at point C. According to Carney, point C must land in the zone between 0.886 and 1.13 of the O-X leg — a convergence of two measurements taken in both directions, that is, the reciprocal ratios 0.886 and 1.13. This double validation is what separates the Shark from the other figures, in which the completion point usually refers to a single leg. To map these levels you use the same tools as for ordinary Fibonacci retracements — the difference is that here you measure two relationships at once.

How to recognise the formation step by step

Step 1 — find the O-X leg and the context

Start with the first clear move, which defines the O-X segment. It need not be long, but it should be legible on your chosen timeframe. Without a distinct point O the whole later grid of measurements loses meaning, because the completion point is referenced back to the O-X leg.

Step 2 — measure the A-B and B-C extensions

Check whether the A-B leg ends point B between 1.13 and 1.618 of the X-A leg, and then whether the B-C leg extends 1.13 to 1.618 of the A-B leg. That excessive C leg is the heart of the formation. Too shallow an extension disqualifies the setup — without the overshoot there is no Shark.

Step 3 — confirm point C in the 0.886–1.13 zone of the O-X leg

The key measurement is where point C sits relative to the O-X leg. The completion point should fall between 0.886 and 1.13 of its range. When the B-C extension and that zone coincide in one spot, you have full convergence — and that extreme is your entry, not any earlier point.

Entry, stop and targets — a hypothetical example

Let us return to the setup in the table above. Once point C completes around 1.0790, you do not enter the Fibonacci level blindly — wait for confirmation from price: a reversal candle, a hammer or a bullish engulfing in the C zone, and only then open the long. The Shark is known for sharp, short-lived bounces, so the reaction usually comes quickly or not at all.

The stop loss goes just beyond point C, a little below 1.0790. When the market breaks the C extreme for good, the structure falls apart, so that is the natural invalidation level. Set targets conservatively, because this is a counter-trend figure: the first take profit is the 38.2 percent retracement of the B-C leg, the second around 61.8 percent. Carney himself stresses that the Shark is a short-term structure that demands active management — many traders close the trade here faster than in calmer formations. Remember, though: the numbers above are purely illustrative and show the logic, not a forecast.

The most common mistakes when trading the Shark

1. Confusing the O-X-A-B-C labelling with the classical X-A-B-C-D and referring the completion point to the wrong leg — in the Shark what counts is the relationship to the O-X leg, not the X-A.
2. Accepting too shallow a B-C leg, below the 1.13 extension — without the excessive overshoot it is not a Shark, just an ordinary pullback.
3. Skipping the double validation of point C and relying on a single ratio instead of the convergence of 0.886 and 1.13 of the O-X leg.
4. Placing the stop loss too tight, right at point C — the reversal zone is often probed by wicks, so the stop belongs clearly beyond the extreme.
5. Holding the position too long — the Shark delivers sharp but brief bounces, so passivity easily turns a profit into a loss.

How the Shark links to the 5-0 pattern

For many traders this connection is the most interesting aspect of the whole figure. According to Carney, the Shark often precedes and effectively builds the structure of the next pattern. The extreme at point C, where the Shark ends, very often becomes one of the points of the next, larger formation — the 5-0 pattern. In other words: if the entry at point C worked, the subsequent move may unfold into a full 5-0 with entry on the 50 percent retracement of the next leg.

From the same family comes the Crab pattern, which, like the Shark, uses the extreme 1.618 extension — the difference is that the Crab refers it to the XA leg and completes at point D. It is worth knowing both, because on the chart they are easy to confuse.

Who this formation is for

Let us be honest: the Shark is not a figure for beginners. It is one of the rarest and hardest harmonic patterns to recognise, and its altered labelling further confuses people used to the classical X-A-B-C-D. Before you reach for it, master support and resistance, price action and the tools of technical analysis. It is a supporting tool, not a standalone system — it works best as one element of a broader plan in which momentum and horizontal levels also provide confirmation.

What to do tomorrow to learn the Shark pattern

1. Open TradingView on EUR/USD at the hourly timeframe and review the recent sharp, asymmetric thrusts, marking points O-X-A-B-C in turn — this exercise trains you to spot the characteristic fin shape before any tradable entry signal even appears.
2. On each candidate, measure two things at once with the Fibonacci tool: whether the B-C leg sits in the 1.13 to 1.618 band of the A-B leg and whether point C lands in the 0.886 to 1.13 zone of the O-X leg, because only that convergence confirms the formation.
3. Set up a simple journal in a spreadsheet with columns for the leg ratios, the entry, the stop loss level and the achieved risk-to-reward ratio, then fill it in after every trade on a demo account so you see real performance rather than an impression.
4. Place a price alert in the completion zone of point C on the pair you are watching, instead of staring at the chart for hours — when price reaches it, you can calmly judge whether a reversal candle confirms the entry or whether it is better to skip the setup.
5. Take at least twenty demo trades on the Shark formation alone and document each one with its result and whether the move went on to develop into a 5-0 pattern — only repeatable performance justifies moving this niche figure to a live account.