RTH vs ETH

The basic definitions

RTH is the primary US stock market session, from 9:30 AM to 4:00 PM Eastern Time. This is when SPY, QQQ and their options trade with the deepest liquidity. ETH covers everything outside that window. For stocks it means premarket and after-hours trading. For futures such as ES and NQ, ETH is the long electronic session that runs from Sunday evening to Friday afternoon, with a short daily pause around 5:00 to 6:00 PM ET.

Futures trade nearly 24 hours, so the cash-session hours are a subset of the futures day. A futures contract therefore has an RTH range and a full-day range, which can differ.

Why the distinction matters

Levels depend on which session you mean. The high of the day on ES can be the RTH high or the high of the entire 24-hour session. They are the same only if the extreme occurred during RTH. Many traders prefer RTH levels for the prior day high, low and close, because that is when the most participants were active, and then separate overnight levels for ETH.

Profiles also depend on the window. The POC of an RTH profile can be very different from the POC of a full-day profile that includes thin overnight trading. Always match the window to the question.

Liquidity differences

ETH is typically thinner. Fewer participants means that news can move price more, spreads can be wider, and moves can reverse quickly when RTH begins. That is why some traders discount ETH extremes as less meaningful than RTH extremes, while others watch them closely because they define the overnight range.

The transition at 9:30 AM ET is also the moment when volume often rises sharply, which is why the first minutes of RTH are watched so closely.

How briefings use the terms

LiquidityLevels briefings describe the overnight session using ETH data and compare it with prior RTH references such as the prior day high, low and close. That lets the reader see how the electronic market positioned itself relative to the previous cash session before the new one starts.

Setting up your charts consistently

Decide whether your daily levels use RTH or the full session, and configure your platform to match. Many charting packages let you switch session templates. Check the prior day high, low and close against the exchange data for a few days to make sure the numbers match what you expect.

If you use both, label them clearly: for example, RTH high and overnight high. Keeping two sets of levels can seem like extra work, but it removes the most common source of confusion when you compare your levels with a commentary or another trader.

Special sessions

Holiday and half-day sessions break the usual pattern. The cash market may close early at 1:00 PM ET, and futures may have a shortened session. Liquidity is thinner, and levels derived from those sessions can be less representative. Many traders note the session type next to the date so a thin day is not treated like a full one.

Worked example

Common mistakes

• Mixing RTH and ETH levels without labeling them.
• Using a full-day profile when the question is about the cash session, or the reverse.
• Forgetting that SPY and QQQ prices in premarket or after hours are thinner and less representative.
• Assuming the daily futures chart uses RTH only. Many platforms default to the full session.

How it connects to ES, NQ, SPY and QQQ

SPY and QQQ options trade only during RTH (with brief extensions on some products), while ES and NQ trade ETH. That mismatch is exactly why futures levels have to be translated into SPY and QQQ terms before the open.

The ES to SPY ratio of roughly 10 and NQ to QQQ ratio of roughly 41 are used to translate ETH futures levels into the ETF prices that matter at the cash open.

Frequently asked questions