Chart School / Recognizing Patterns
Triangles and ranges
Lesson 11 of 14 · about 1 min read, plus practice · Glossary
A range contains repeated movement between approximate boundaries. A triangle has converging boundaries as swings narrow; it need not be symmetrical. Review the prior trend, interval and number of touches before labeling a shape. Narrowing swings show what happened within that sample, not which side must break next. Some chart readers wait for a close outside a boundary or a retest, but either can fail. Do not redraw boundaries after every outcome to make a prediction appear correct.
Worked fictional example
Fictional River records highs of $54, $53 and $52 while lows rise from $46 to $48 to $49. The narrowing space illustrates a triangle, with direction still unresolved at the final observation.
On a small screen, scroll the chart horizontally to read every label.
Observation order / daily periods →
Accessible data table and chart description
Separate fictional daily OHLCV illustration for Triangles and ranges. Hollow body: close at or above open; filled body: close below open. Table provides exact values.
| Date UTC | Open | High | Low | Close | Volume |
|---|---|---|---|---|---|
| 2024-01-01 | 46 | 47 | 45 | 46 | 100 |
| 2024-01-02 | 46 | 55 | 45 | 54 | 120 |
| 2024-01-03 | 54 | 55 | 47 | 48 | 0 |
| 2024-01-04 | 48 | 54 | 47 | 53 | 160 |
| 2024-01-05 | 53 | 54 | 48 | 49 | 180 |
| 2024-01-06 | 49 | 53 | 48 | 52 | 200 |
| 2024-01-07 | 52 | 53 | 49 | 50 | 220 |
Legend: hollow body = close ≥ open; filled blue body = close < open. Wick = low to high. Direction is also readable from the table, without color.
What could invalidate this interpretation?
A proposed triangle becomes less useful if swings cease to narrow or repeated moves cross its drawn boundaries.
A counterexample
Price can poke above a narrowing boundary and return inside. An upward prior trend does not guarantee an upward exit.
Check your understanding
Further learning
Original FinanceFD explanations and drawings. For additional context, see Fidelity’s overview of technical analysis, Fidelity’s RSI guide and Investor.gov’s investing introduction.
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