> ## Content Index
> Fetch the complete content index at: https://www.propfirmduel.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# The 80% rule
- URL: https://www.propfirmduel.com/strategies/eighty-percent-rule/
- Published: 2026-10-07T22:25:00.000Z
- Updated: 2026-10-08T02:59:49.000Z
- Description: A Market Profile rule: if price opens outside yesterday's value area and then spends two 30-minute periods back inside it, it often travels across the whole value area.
- Author: Prop Firm Duel
- Tags: Volume and value strategies, #strategy, #school-volume, #level-advanced, #Import 2026-10-07 22:49

TargetStopPrice back above the averageReclaim holds

Example drawing, not live market data.

1Where's the level?

Yesterday's value area.

2What's the trigger?

After an open outside it, two 30-minute candles in a row (counted from 9:30 ET) close inside value, before 3:00 PM ET.

3Where is it wrong?

Just outside value, beyond the edge price came back through.

4Where does it end?

The far edge of the value area.

Markets

Index futures

Timeframes

30m

Sessions

New York

Also called

value area 80% rule

## What it means

A Market Profile rule: if price opens outside yesterday's value area and then spends two 30-minute periods back inside it, it often travels across the whole value area.

## How it is confirmed without repainting

Both 30-minute periods must close.

## When it fails

A close back outside value.