What is a bull flag pattern? The pole and the flag
A bull flag is a continuation pattern: it suggests that a strong move up is resting, not ending. It has two parts, drawn in the left panel at the top of this page. The pole is a steep, fast rise. The flag is a small block of candles that drifts sideways to slightly down between two roughly parallel lines, against the direction of the pole.
Classic references describe the flag as a small rectangle tilted against the prior trend, and require a sharp move on heavy volume before it. Without that move there is no flag, only a range. The wider family is in the chart patterns guide.
- Pole (flagpole)
- The sharp, nearly straight move before the pause. Its length in price is used for the measured-move target.
- Flag
- A short, shallow pause between two parallel lines that slope against the pole: down in a bull flag, up in a bear flag.
- Pennant
- The same pause shaped like a tiny symmetrical triangle, with lines that converge instead of running parallel.
- Breakout
- A candle that closes beyond the flag’s upper line (bull flag) or lower line (bear flag). A wick through the line is not enough.
- Measured move
- A target convention: add the pole’s length to the breakout level. A planning estimate, not a forecast.
The pole: a sharp move on strong volume
The pole is what separates a flag from an ordinary wobble. It should be fast and obvious: several large candles in a row with small pullbacks or none, often starting with the break of a level or a gap. If you have to squint to see the pole, there isn’t one.
Volume tells you whether real buying drove the move. The classic profile has three steps: heavy volume on the pole, lighter volume while the flag drifts, and volume expanding again on the breakout. A breakout on thin volume deserves more doubt than one on a surge.
The drawing below shows what “strong” looks like: most volume bars sit near a dashed average line, and the breakout bar is about three times taller, tagged RVOL 3.0. Relative volume (RVOL) is volume divided by its average; the relative volume guide covers how to measure it.
The flag: shallow, orderly and short
A healthy flag looks calm next to the pole: small candles, overlapping bodies, a gentle slope against the trend. Buyers are taking a breath, and sellers cannot push price far. The drawing below shows the same idea as an orderly pullback in small candles that then closes back up.
Pattern researcher Thomas Bulkowski also notes that flags often appear near the middle of the whole move, which he calls a half-staff flag. That is where the measured-move target comes from. Three checks keep you honest:
- Depth: a common rule of thumb is that the flag gives back well under half of the pole. Once it retraces more than half, many traders stop calling it a flag.
- Shape: tight and parallel. Bulkowski separates tight flags from loose ones that meander, poke outside their lines or look jagged, and favors the tight kind.
- Length: short compared with the pole. On daily charts Bulkowski uses under three weeks; other references allow up to 12 weeks, ideally one to four. Intraday there is no official bar count: a pause that runs far longer than the pole took to form is turning into a range.
Bull flag vs pennant, and when they turn into triangles
A pennant follows the same kind of pole, but the pause narrows into a tiny symmetrical triangle instead of a sloping channel, as in the right panel at the top of this page. The trading logic is identical: a close above the pennant is the entry, the stop goes under its low, and the pole sets the measured move.
The difference matters when the pause drags on. Past roughly 12 weeks on a daily chart, references reclassify a flag as a rectangle and a pennant as a symmetrical triangle. Those are slower patterns with their own rules, covered in the triangle patterns guide.
The drawing below puts a bull flag next to an ascending and a symmetrical triangle, each with its breakout. All three are pauses inside a trend; the flag is simply the shortest and steepest.
The bear flag: the mirror image
A bear flag is the same pattern upside down: a sharp drop on heavy volume (the pole), then a small channel drifting up against it, then a close below the channel’s lower line. A bear pennant is the triangle version. The bounce inside a bear flag is usually weak and on light volume, which is the point: sellers are resting, not leaving.
Hypothetical: a stock falls from $60.00 to $57.00 on heavy volume, a $3.00 pole. It drifts up in a rising channel to $57.90, then a candle closes at $57.30, below the channel’s lower line at $57.40. A short at $57.30 with a stop above the flag high, at $58.00, risks $0.70 per share; the measured move is $57.40 − $3.00 = $54.40.
Shorting adds a risk of its own: a stock can keep rising, so the stop is not optional. The short selling guide covers borrowing and squeezes. If you don’t short, a bear flag is still useful as a warning not to buy the bounce.
How to trade a bull flag: entry, stop, target and size
Hypothetical, on a 5-minute chart: a stock runs from $80.00 to $83.00 in six candles on about three times its average volume. That $3.00 rise is the pole. It then drifts down for seven small candles in a narrow channel to a low of $82.10, giving back $0.90, or 30% of the pole, on shrinking volume.
The drawing below shows the plan: a bracket on the pole, the same length projected up from the breakout, the flag’s two channel lines and a dotted stop under its low. The measured move is an estimate: price often stalls at a level first, and sometimes runs past it.
UpTickFlow, our invite-only TradingView indicator, follows the same close-first logic, so weigh this accordingly. It does not detect flags or any chart pattern. It waits for a candle to close at a level, draws an entry, a stop and a target before the trade, scores the setup from 0 to 100 and stays quiet in chop: a second check on your flag, not a scanner.
- Entry: wait for a candle to close above the flag’s upper line. Here the line sits at $82.50 and a candle closes at $82.60 as volume picks up. Some traders wait for a retest of the line from above instead, accepting a worse price for more confirmation.
- Stop: just under the flag’s low, where the pattern is clearly broken: $82.00, or $0.60 of risk per share.
- Target: add the pole to the breakout level: $82.50 + $3.00 = $85.50. A more conservative variant adds the pole to the flag’s low instead: $82.10 + $3.00 = $85.10.
- Room: the prior day’s high at $84.00 sits in the way, so many traders take a first target there, $1.40 from the entry or about 2.3R, and treat $85.50 as a stretch. If the nearest level pays less than your minimum, skip the trade. See the risk-reward ratio guide.
- Size: risking 1% of a $10,000 account, or $100, at $0.60 a share allows 166 shares, so a stop-out costs about $100. The position size calculator does the math.
When a “flag” is really a reversal: too deep or too long
The most expensive mistake is calling any pullback after a rally a flag. Same hypothetical stock: after the $80.00 to $83.00 pole, price slides to $81.20 in large red candles on rising volume. It has given back $1.80, or 60% of the pole, and sellers are clearly active. A falling line drawn over those highs is not the top of a flag, and buying its break means buying into a possible reversal.
Treat it as something other than a flag when you see these signs:
- Depth: the pullback erases more than half of the pole, or breaks back below the level where the pole started.
- Volume: the down candles inside the “flag” carry more volume than the pole did. That is real selling, not resting.
- Time: the pause lasts far longer than the pole. Momentum has faded and the pattern is becoming a range; trade it with range trading rules or leave it.
- Structure: a lower high followed by a break of the last higher low turns a pause into a possible trend change, as the market structure guide explains.
- Context: the flag sits right under a daily resistance level, or the higher timeframe points the other way. Check with multi-timeframe analysis.
Failed bull flags: false breakouts and what a loss looks like
Even a textbook flag fails often, and the failure looks exactly like the setup at first. Same hypothetical: the candle closes at $82.60 and you buy 166 shares. The next candle closes back inside the flag at $82.20, and two candles later price trades through $82.00. You are out for about $100, or 1R: planned and survivable.
Why it happens: the top of a flag is where many buy stops sit. They fill on the break, and if no new buyers follow, price falls back and the trapped buyers sell, which can push it lower fast. A breakout candle with a long upper wick, or one on weak volume, is a common early warning. The breakout trading strategy guide covers false breakouts in more detail.
What turns a small loss into a big one is the reaction: moving the stop lower “to give it room”, buying more as it falls, or holding a broken flag because the pole looked so strong. Once the flag’s low breaks, the pattern is gone. A flag can also fail by stalling just above the line; decide before you enter how many candles you will give it.
Bull flag checklist, and how to draw one on TradingView
On TradingView, draw a flag with the Parallel channel tool and a pennant with two Trend lines. TradingView’s help center notes that you can set an alert for when price crosses a parallel channel, so you don’t have to watch every candle; see TradingView alerts. Before you act, run the list:
- A clear pole: fast, obvious and on strong volume.
- A shallow, tight, short flag: well under half the pole, small candles, lighter volume, not much longer than the pole.
- Room: no major resistance just above the flag, and the higher timeframe pointing the same way.
- A candle closes above the flag’s upper line, ideally on rising volume.
- Stop under the flag’s low, first target at the nearest level or the measured move, and a size that makes a stop-out a small, fixed loss.