RTH vs Globex in Index Futures: What Changes
Updated September 20, 2026
One contract, two sessions
Index futures such as ES or NQ trade almost twenty-four hours a business day. The regular session, abbreviated RTH for Regular Trading Hours, is the window that matches the US stock market: 9:30 to 16:00 New York time.
Everything else is the extended electronic session, or ETH. In CME futures it is called Globex, after the name of the electronic platform where they trade. It is the same contract, the same account and the same order book; what changes is who is in front of the screen.
The practical difference is participation. The regular session concentrates most of the institutional volume. On Globex the book is thinner and a few contracts move price more. That is why almost all structure statistics are computed on RTH.
What exactly the overnight session is
Overnight is the stretch of Globex from one day's regular close to the next day's regular open. It includes the European early morning and the Asian day, and it is where most of the news the US market cannot digest live comes in.
That stretch produces two things that are used all day: the overnight range, with its high and low, and the opening gap, which is the distance between yesterday's regular close and today's open.
It is worth fixing the hours in writing, including the time zone and the holiday calendar. Without that, two people can call different stretches overnight and get figures that cannot be compared.
Where the day's extreme really forms
If the regular session concentrates the volume, it would be logical to think the day's extreme is decided there. The table distributes ES's daily high and low across the segments of the 24-hour cycle, over 4,175 sessions, and that is not what comes out.
The London segment produces the most extremes: 37.0% of the day's highs and 37.2% of the lows, over those 4,175 ES sessions. New York trails, with 29.4% of highs and 27.8% of lows.
Asia contributes 15.5% of highs and 22.3% of lows: it is the segment with the clearest imbalance between the two extremes. The minutes left between close and open, grouped as off-session, take 18.0% of highs and 12.7% of lows.
The reasonable reading is not that London matters more than New York, but that the day's extreme is frequently decided before the regular session opens. Anyone looking only at the RTH chart is looking at the segment where fewer extremes form than in the European one.
Where the day's high and low form
ES
| Session | Day's high | Day's low | Sessions |
|---|---|---|---|
| Asia | 15.5% | 22.3% | 4,175 |
| London | 37.0% | 37.2% | 4,175 |
| New York | 29.4% | 27.8% | 4,175 |
| Outside sessions | 18.0% | 12.7% | 4,175 |
n = 4,175 · 2010-06-07 to 2026-09-15 · exchange data
Split of the daily extreme across the three sessions of the 24-hour cycle. 'Outside sessions' are the minutes left between close and open.
The night's direction and what the following day does
The second natural question is whether what happens overnight marks the day. The table measures the direction of the overnight stretch, from yesterday's regular close to today's open, and then looks at how often the regular session kept moving in that same direction.
When the night is up, continuation in ES ranges from 50.8% on Wednesday, over 829 sessions, to 55.9% on Friday, over 805 sessions. Monday shows 54.7% with 819 sessions, Tuesday 53.5% with 825 and Thursday 52.9% with 826.
When the night is down, the values fall below those: 42.6% on Monday, 49.5% on Tuesday, 44.1% on Wednesday, 46.3% on Thursday and 47.1% on Friday, with the same ES samples.
All of these figures orbit around one half. Put plainly: knowing the night's direction barely tilts the balance of the day, and it certainly does not decide it. It is context data, not a filter that works on its own.
Does the overnight direction continue in the regular session?
ES
| Day | Overnight up | Overnight down | Sessions |
|---|---|---|---|
| Monday | 54.7% | 42.6% | 819 |
| Tuesday | 53.5% | 49.5% | 825 |
| Wednesday | 50.8% | 44.1% | 829 |
| Thursday | 52.9% | 46.3% | 826 |
| Friday | 55.9% | 47.1% | 805 |
n = 4,104 · 2010-06-07 to 2026-09-15 · exchange data
Overnight direction = from yesterday's regular close to today's open. The percentage is how often today's regular session then moved in that same direction.
What changes in your levels depending on the session you choose
The Initial Balance, which is the range of the first sixty minutes of the regular session, only makes sense with a defined opening time. Computed on the full session it stops measuring what its name says.
The same goes for the Value Area and the POC. Including the night adds hours of low volume that shift the day's most traded price. Two charts of the same contract can show a different POC just because of that choice.
And the gap depends entirely on the reference. Measured against the prior regular close it gives one number; measured against the last early-morning price it gives another. Before comparing two statistics, confirm that both use the same session.
What this measurement does not say
The distribution of extremes does not say at exactly which minute the high occurred within each segment, nor how far it stood from the rest of the day. A session can set its high in Asia by a few points and spend the rest of the day far from there.
It also says nothing about profitability. That the extreme forms outside the regular session does not mean it can be traded there at the same cost: on Globex the spread is wider and book depth is lower.
Period biases weigh in. The range runs from June 2010 to September 2026 and mixes very different regimes. The continuation by day of the week splits 4,104 ES sessions into five boxes, so a difference of a couple of points between neighboring days should not be read as a rule.
Finally, the segment hours are a convention. Moving the London cutoff by half an hour redistributes extremes from one column to another without the market having changed anything.
How to work with both sessions
A reasonable routine uses RTH for structural levels and Globex for context: where price moved while you were not watching, what range the night left and where the open stood relative to the prior close.
Document the definition next to each figure, just like the sample. A futures statistic without a declared session is not reproducible and, therefore, not comparable with any other.
This text is informational material on how to read market data. It is not personalized investment advice or a recommendation on any instrument. Past results do not anticipate future ones, and trading futures involves risk of loss.
Frequently asked questions
- What are the ES regular session hours?
- 9:30 to 16:00 New York time, on US stock market business days. The rest of the 24-hour cycle is the extended electronic session.
- What does Globex mean in futures?
- Globex is CME's electronic platform and, by extension, the name used for the session that takes place outside regular hours. It is the same contract, with less volume and wider spreads.
- At what time does the day's high form in ES?
- Over 4,175 ES sessions, 37.0% of daily highs form in the London segment and 29.4% in the New York one. Asia contributes 15.5% and the off-session minutes 18.0%.
- Does the overnight session's direction predict the day's?
- Barely. In ES, when the night is up, the regular session continues in that direction between 50.8% of the time on Wednesday, over 829 sessions, and 55.9% on Friday, over 805. It is too close to one half to treat as a rule.
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