Three Inside Up/Down (CDL3INSIDE)

Summary

A three-candle reversal pattern: a long real body, then a short real body totally engulfed by it (a harami), then a third candle of opposite color to the first that closes past the first candle's open. Signals a bullish reversal (three inside up, significant in a downtrend) or a bearish reversal (three inside down, significant in an uptrend).

Chart

Reference data (CSV) · Chart (SVG)

Chart metadata i

Outputs

outInteger: pattern_bull_bear · zero · positive · negative

Notes

Does not verify the prior trend the pattern classically assumes (three inside up is meaningful in a downtrend, three inside down in an uptrend).
Bulkowski's testing found Three Inside Up succeeds as a bullish reversal 65% of the time (rank 20 of 103 overall) and Three Inside Down succeeds as a bearish reversal 60% of the time (rank 56 of 103) — both meaningfully better than a coin flip. (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 inside up (bullish reversal, first candle black), -100 for three inside down (bearish reversal, first candle white), 0 when no pattern. Computed as -candlecolor(1st)*100

Output Values

What candlestick values mean: Candlestick Outputs. The function's flags declare which values it can return: rW7.

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

Properties

Numerical Stability: Start-Independent


☐ Overlap Input
✅ Independent Y-Axis i
✅ Candlestick i
☐ Display Shift


☐ Can Output NaN or ±Inf
☐ Identity at Period 1
☐ Uses Transcendental
☐ Input Must Be Positive

Example

#include <stdio.h>
#include <ta_libc.h>

int n = 252;
double open[252]; /* your data, oldest first */
double high[252]; /* your data, oldest first */
double low[252]; /* your data, oldest first */
double close[252]; /* your data, oldest first */
int out[252];
int outBegIdx, outNBElement;

TA_Initialize();
TA_CDL3INSIDE( 0, n - 1, open, high, low, close, &outBegIdx, &outNBElement, out );
printf( "%d values from bar %d; last out = %d\n", outNBElement, outBegIdx, out[outNBElement - 1] );

Rust

use ta_lib::Core;

let open = vec![0.0; 252]; // your data, oldest first
let high = vec![0.0; 252]; // your data, oldest first
let low = vec![0.0; 252]; // your data, oldest first
let close = vec![0.0; 252]; // your data, oldest first
let mut out = vec![0i32; 252];

let core = Core::new();
let range = core.cdl3inside(0, open.len() - 1, &open, &high, &low, &close, &mut out)?;
println!("{} values from bar {}; last out = {}", range.count, range.beg_idx, out[range.count - 1]);

Java

import io.github.talib.Core;
import io.github.talib.OutRange;

double[] open = new double[252]; // your data, oldest first
double[] high = new double[252]; // your data, oldest first
double[] low = new double[252]; // your data, oldest first
double[] close = new double[252]; // your data, oldest first
int[] out = new int[252];

Core core = Core.DEFAULT;
OutRange r = core.cdl3inside(0, open.length - 1, open, high, low, close, out);
System.out.println(r.count() + " values from bar " + r.begIdx() + "; last out = " + out[r.count() - 1]);

using System;
using TALib;

var open = new double[252]; // your data, oldest first
var high = new double[252]; // your data, oldest first
var low = new double[252]; // your data, oldest first
var close = new double[252]; // your data, oldest first
var outInteger = new int[252];

var core = Core.Default;
OutRange r = core.Cdl3inside(0, open.Length - 1, open, high, low, close, outInteger);
Console.WriteLine($"{r.Count} values from bar {r.BegIdx}; last outInteger = {outInteger[r.Count - 1]}");

TypeScript

import { cdl3inside } from 'ta-lib';

const open = new Float64Array(252); // your data, oldest first
const high = new Float64Array(252); // your data, oldest first
const low = new Float64Array(252); // your data, oldest first
const close = new Float64Array(252); // your data, oldest first

const { begIdx, values } = cdl3inside({ open, high, low, close });
console.log(values.length + ' values from bar ' + begIdx + '; last values = ' + values[values.length - 1]);

Implementation

Added in 0.4.0.

TA-Lib Definition: cdl3inside.c · cdl3inside.yaml

Native	File
C	`ta_CDL3INSIDE.c`
Rust	`cdl3inside.rs`
Java	`Core_CDL3INSIDE.java`
C#	`Core_CDL3INSIDE.cs`
TypeScript	`cdl3inside.ts`

Python: talib.CDL3INSIDE, see ta-lib-python.

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

Aliases

Three Inside Up/Down, Three Inside, Three Inside Up, Three Inside Down