Define the symmetrical triangle before studying its exit: context, boundaries, volume and invalidation belong in the same written research record.
What defines the symmetrical triangle
A symmetrical triangle brings falling reaction highs and rising reaction lows toward an apex. It needs separate touches on both lines rather than a line through every candle. The two slopes need not be numerical mirror images. What matters is a narrowing range between boundaries that point toward each other.
The preceding trend and duration
This compression describes balance inside a prior trend, but neither boundary determines the eventual direction. Study both an upward close through resistance and a downward close through support. A late move near the apex can be little more than the lines meeting rather than a strong expansion.
Use the same chart interval for every touch. A formation visible on daily candles can contain shorter swings on an intraday chart; those are separate samples. Count the duration and record the touches used, so another reader can reconstruct the boundaries.
A close beyond the boundary
This illustration resolves upward, through the falling upper boundary. Use the line value on the actual breakout session, not its starting height. For a downward resolution, use the rising lower boundary on that session and subtract the height when illustrating an objective.
| Measurement | Value |
|---|---|
| Event session (leftmost bar is session 1) | 34 |
| Boundary at the exit | 33.70 |
| Close of the exit session | 34.55 |
| Distance beyond the boundary | 2.52% |
| Initial formation height | 6.00 |
| Conventional projected level | 39.70 |
Illustrative objective = 33.70 + 6.00 = 39.70The projection is a geometric reference. It is not a price forecast, a probability or an instruction to hold until that level. Describe what would contradict the premise before comparing the potential distance with the risk.
Volume through the formation
Compare volume with this stock’s own recent activity and inspect the bars on which it expands. Contracting activity during a pause and expansion at its exit can support a conventional reading, but volume does not choose the direction. A large session may reflect an event, rebalancing or an isolated trade.
| Measure | Hypothetical value |
|---|---|
| Average, first 5 sessions of the symmetrical triangle | 103.2 |
| Average, last 5 sessions before the breakout | 57.0 |
| Breakout session | 240.0 |
| Breakout ÷ 20-session average | 2.82 |
The displayed relative-volume calculation divides the event’s volume by the average of the 20 sessions ending with that event; it includes the event itself. It differs from a comparison with the prior 20 sessions and from an intraday comparison at the same clock time.
When the conventional reading fails
The second drawing closes above the upper line, returns inside and later breaks the lower line. A narrowing shape can produce both breaks. The first break loses its directional premise when price moves back through the formation and breaches the opposite boundary.
Separate this shape from nearby patterns
Flags have roughly parallel boundaries and need a sharp pole. Pennants also converge, but their short pause follows a distinct pole. A broader symmetrical triangle need not have that pole or that brief duration.
Record a reproducible chart observation
A useful chart record includes the unsuccessful cases. Define your rules before collecting examples and retain the same price scale, adjustment basis and candle interval throughout the sample.
- Record the preceding swing direction, formation duration and each boundary touch.
- Write the exact close-based confirmation and the opposite boundary or swing that invalidates it.
- Compare event volume with its named denominator, and review both resolving and failed drawings.
- Check whether a scheduled event, such as an earnings report, falls inside the window you are studying; using earnings dates in research covers where such dates come from.
- Inspect the same stock on the Symbol Analysis guide, then record your observations in a trading journal.
These guides teach manual chart interpretation. A near-high or range screen lists candidates to inspect; it does not identify this formation.
Continue with
- Support, resistance and trendlinesHow horizontal levels and sloping lines are drawn and tested.
- Breakouts and pullbacksWhat a close beyond a level shows, and how retests are read.
- Put stock volume in contextCompare a session’s volume with the same stock’s usual activity.
- Candlestick patternsSingle- and multi-session candle shapes read alongside chart patterns.
- Stop-loss and profit targetsWhere invalidation levels and objectives fit in a written plan.
Sources
Read our data and methodology notes for calculation context. This guide explains research tools and observations. It does not recommend a trade or investment.