What qualifies
- Pole: a rise of at least 8% (or 3× the 14-day average true range, whichever is bigger) over 3 to 20 days, ending at the highest high of the last 25 days.
- Flag: 3 to 15 days since that high, with no new high, giving back no more than 50% of the pole, and today’s close still above the flag’s low.
- Breakout level: the highest high of the flag (excluding today). A close above it is listed as Breaking out.
- Bear flag: the mirror image: a drop of at least 8% (or 3× ATR), then a 3–15 day bounce that retraces at most half of it.
- Quality rewards a bigger pole, a shallower flag, lower volume in the flag than in the pole, and a flag of about a week.
How to read a flag
A flag is a pause after a strong move. Traders watch for price to leave the flag in the direction of the pole, ideally on rising volume, and often place a stop under the flag’s low (above its high for a bear flag). The Flag vol × column shows the flag’s average volume against the pole’s: under 1× means volume dried up during the pause, which many traders like to see.
Patterns are found mechanically on daily candles from the data provider. Not investment advice.
Frequently asked questions
What is the difference between a bull flag and a pennant?
Both are short pauses after a sharp move. A flag drifts sideways or slightly against the trend in a channel; a pennant narrows into a small triangle. This screener treats both as flags as long as they meet the rules above.
What does the quality score mean?
It’s a 0–100 score of how cleanly the pattern fits the rules above (for example, how tight the flag is, how round the cup is, or how closely the two lows match). It isn’t a probability and says nothing about what price does next. Use it to sort the list, then look at the chart: click a symbol to open it on FreeCharting.
Are these patterns reliable?
Chart patterns are a way to describe price action, not a prediction. Many fail, and they work differently in different markets. The detection is mechanical: a pattern can qualify on the numbers and still look wrong to your eye, and a pattern you’d draw by hand may miss one rule. Nothing here is investment advice.
Which markets can it scan?
Four, picked with the Market buttons above the table. Crypto (the default) scans the 250 busiest USDT pairs on Binance. Crypto perps scans the 200 busiest USDT perpetual futures on OKX. Both are free public data and need no key. US stocks scans about 600 US stocks and ETFs with your own free Alpaca key, and CME futures scans about 25 front-month CME Group contracts (stock indexes, Treasuries, oil, gas, metals, grains, livestock, currencies and CME bitcoin) with your own free Massive key.
Why do stocks and futures need a key?
Stock and futures prices are licensed data, so a website can’t hand them out for free. Alpaca (for stocks) and Massive (for futures) give anyone a free data key. Your key is saved only in your browser and sent only to that provider. See how to get a free Alpaca key and how to get a free Massive key for futures.
Is the data real-time?
Crypto and crypto perps are live from Binance and OKX, on daily candles that start at 00:00 UTC (today’s candle is still forming). Alpaca’s free stock data is 15 minutes behind the market, and Massive’s free futures plan is 8 hours delayed. Turn on auto-refresh next to the results to update the table in place every 30 seconds, minute or 5 minutes.