Triangle Breakouts: Probability by Type

Triangles are continuation patterns — most of the time. But "most" varies sharply by type: ascending triangles break upward 65-75% of the time, symmetrical 50-55%, and the direction is roughly a coin flip. Treating all triangles the same loses money. Trade them by type.

Ascending Triangle (Bullish Continuation)

Structure: flat upper boundary (resistance), rising lower boundary (support). Buyers step in at progressively higher lows; sellers defend a fixed level.

Breakout direction: up 65-75% of the time in tested US equity data. Volume: declining into the apex, spike on the breakout (1.5-2x average).

Entry: close above the flat resistance. Stop: below the rising support (or below the most recent higher low for tighter placement). Target: height of the triangle (widest part) projected up from the breakout.

False-breakout risk: 25-35%. The first break above resistance often retests it from above before continuing. Wait for the retest entry when possible — hit rate rises 10%.

Descending Triangle (Bearish Continuation)

Structure: flat lower boundary, descending upper boundary. Sellers step in at lower highs; buyers defend a fixed level.

Breakout direction: down 65-75%. Volume: declining into apex, spike on the breakdown.

Entry: close below flat support. Stop: above the descending resistance. Target: height of triangle projected down.

Mirror of the ascending triangle — same probabilities, opposite direction. In strong uptrends, descending triangles fail more often (40%+); require the broader trend to be down before trading the breakdown.

Symmetrical Triangle (Directional Coin Flip)

Structure: converging upper and lower boundaries, both sloped toward the apex. Neither buyers nor sellers dominate.

Breakout direction: up 50-55%, down 45-50% — essentially a coin flip. Do not pre-commit to a direction.

Trade the break, not the prediction. Entry: close outside the boundary. Stop: at the apex or beyond the opposite boundary. Target: height of the triangle (widest part) projected from the breakout.

Symmetrical triangles have the highest false-breakout rate (40-50%). Require: (1) volume spike on the break, (2) close outside the boundary, (3) retest of the boundary within 3 candles. Without all three, skip the trade.

The Apex Problem

Triangles fail most often near the apex, where volatility is lowest and the pattern is most "obvious." Breakouts that occur in the middle 60% of the pattern's horizontal range (measured from formation start to apex) hit 60-70%; breakouts in the final 20% before the apex hit 45-55%. Trade the middle, not the apex.

Volume Across All Types

Volume declines into the apex; breakout volume ≥ 1.5x the 20-period average. Low-volume breakouts fail 55-65% across all types.

Target Measurement

Measure the widest vertical distance between boundaries early in the pattern, project from the breakout point. Minimum target; strong breakouts extend 1.5-2x.

Common Errors

• Pre-selecting direction on symmetrical triangles — the pattern breaks, it does not predict.
• Entering at the apex; wait for the break in the middle 60% with volume confirmation.

Triangle edge is type-specific. Ascending and descending favor continuation; symmetrical requires trading the break.