Prior-Day High and Low

What they are

Each trading session produces a high, a low and a close. When the next session opens, those three numbers become reference points. The prior-day high marks where the market previously found its upper extreme and the prior-day low its lower one. Together they define yesterday range.

They are popular because they are objective, require no calculation, and appear on virtually every chart. Because so many market participants see the same levels, they often become a shared reference for describing where the market is.

Defining the session

The first decision is which session counts. Many traders use the regular trading hours session, 9:30 AM to 4:00 PM ET, to define the prior-day high and low, since that is when most participants traded. Others use the full 24-hour futures session, which also includes the overnight range.

The two can differ significantly. If the overnight session made a new high above the RTH high, the full-session high is higher. Stating the convention avoids confusion, and some traders track both sets of levels.

How traders use them

The most common use is to describe the opening. An open inside the prior range suggests the market is returning to balance. An open above the prior high or below the prior low suggests a move out of the previous range, which traders then judge as acceptance or rejection.

Breakout and fade ideas are built around these levels. Some traders watch for price to accept above the prior high as a sign of strength. Others watch for failed breaks above the high as a sign of weakness. Neither is reliable on its own, and both depend on how price behaves once it gets there.

The midpoint of the prior range, and its quartile levels, are also used as reference points. The free prior-day range calculator on this site computes them from a high, low and close.

Limitations

Because every trader sees these levels, price sometimes whips around them. Stops can cluster just beyond them, which can lead to brief spikes and reversals. Several traders call these stop runs. Whether that is a deliberate effect or simply the result of many orders in the same place, price frequently reacts in a noisy way near these levels.

They also say nothing about volume or time. A high set on a thin spike is treated the same as one set on heavy trading unless you add other tools.

A routine for using prior-day levels

Each morning, note the prior high, low and close, the midpoint and the 25 and 75 percent levels. Then compare the overnight session with them: inside the range, above, below, or testing an edge. Finally, decide in advance how you will define acceptance beyond each edge, such as a number of closes on your timeframe.

During the session, record what happens at each level in a simple log. After a few weeks you will see which levels the market respects in your instrument and which it ignores.

Prior-day levels versus weekly and monthly levels

Longer-term highs and lows, such as the prior week or prior month, work the same way but at a different scale. They tend to matter when price approaches them, since fewer traders have them in mind than the daily levels but those who do often have larger positions. When daily and weekly levels coincide, the area draws more attention. When they do not, the daily levels usually dominate intraday behavior.

Worked example

Common mistakes

• Using different session definitions on different days.
• Treating the prior-day high or low as a guaranteed barrier.
• Ignoring the time and volume spent at the extreme. A brief spike is not the same as a tested level.
• Placing all decisions on one level without context from structure, news or the overnight range.

How it connects to ES, NQ, SPY and QQQ

SPY and QQQ prior-day highs and lows come from their own regular sessions. ES and NQ levels can be translated into approximate SPY and QQQ terms by dividing by roughly 10 and 41. The translation drifts with basis, so always check the ETF chart for the actual level.

LiquidityLevels briefings frame the overnight range relative to the prior session levels so the reader can see whether the market is inside, testing or outside yesterday range before the open.

Frequently asked questions