Three Outside Up/Down (CDL3OUTSIDE)

Summary

A three-candle pattern: an engulfing pair (candle 2's body fully engulfs candle 1's body) followed by a third candle that confirms in the engulfing direction. Signals a bullish reversal (Three Outside Up) or bearish reversal (Three Outside Down).

Notes

Does not verify the prior trend the pattern classically assumes (three outside up is meaningful in a downtrend, three outside down in an uptrend).
Bulkowski's testing puts Three Outside Up at a 75% bullish-reversal success rate versus 69% for Three Outside Down — both notably higher than the closely related Three Inside Up/Down (65%/60%), i.e. the engulfing "outside" variant tests as more reliable than the harami "inside" variant. (thepatternsite.com)

Inputs

inOpen — Open price of each bar
inHigh — High price of each bar
inLow — Low price of each bar
inClose — Close price of each bar

Outputs

outInteger — +100 for Three Outside Up (bullish), -100 for Three Outside Down (bearish), 0 when no pattern. Emits both signs; value is candle i-1's color * 100

Output Values

Value	Meaning
-100	Three Outside Down — bearish reversal, most meaningful after an uptrend
0	No pattern
100	Three Outside Up — bullish reversal, most meaningful after a downtrend

Properties

Numerical Stability: Start-Independent


☐ Overlap Input
✅ Independent Y-Axis i
✅ Candlestick i
☐ Can Output NaN or ±Inf
☐ Identity at Period 1

Implementation

TA-Lib Definition: cdl3outside.c · cdl3outside.yaml

Native	File
C	`ta_CDL3OUTSIDE.c`
Rust	`cdl3outside.rs`
Java	`Core_CDL3OUTSIDE.java`

TA-Lib is also available for Python, R and more using a wrapper.

Aliases

Three Outside Up/Down, Three Outside