Gently converging highs and lows, each boundary tested at least three times; completes with a breakout above the upper line or a breakdown below the lower line.
A symmetrical triangle is a contracting range: lower highs and higher lows that converge toward an apex. It is the only diagonal pattern classical chartists such as Kibar feature, and only when the boundaries are not steep, because sloping lines make breakouts harder to judge.
The direction is not known in advance; the trend filter decides whether a breakout or a breakdown counts.
How we define it
Upper line falling and lower line rising, each through at least 3 swing tests and tested again in the last 40% of the pattern
Shallow: each boundary moves at most 60% of the starting height over the pattern; both sides converge
No close outside the lines before the break; the breakout or breakdown comes before 3/4 of the way to the apex (Edwards & Magee)
Minimum length: 2 months on 1D, 3 months on 1W, 10 days on 4H (from the first boundary test to the breakout or breakdown)
Breakout (up) / breakdown (down): the first candle close above the upper boundary or below the lower boundary by at least 3% on 1D and 1W (1.5% on 4H), following Edwards & Magee
Failed breaks: a breakout or breakdown that closes back inside the boundary within 6 candles on 4H, 5 on 1D or 3 on 1W is removed from the list
Trend filter: breakouts only above the 200-period EMA (40-week EMA on 1W), breakdowns only below it
Watchlist: the pattern meets the length and test rules, has not broken yet, and price is within 3% (or 1 ATR, at most 6%) of the boundary
No recent breakout or breakdown
No symmetrical triangle has completed recently. See all patterns.