Do you start the day with Extended Hours trading

[71Warhawk]

Do you start the day with Extended Hours trading ? Does it make a difference?

 

[rad14733]

@71Warhawk Yes, most traders use Extended Hours because it shows market structure, especially what has transpired during the Asia and European sessions... It also helps smooth indicators because they have ample data to process...

 

[useThinkScript]

Do you start your charts with Extended Hours (ETH) included? Does it make a difference?

Premarket:
Obviously, when doing premarket analysis, extended hours is critical. As @rad14733 stated, given how correlated Asia and London activity has been, these extended hours provide a big heads-up for the US Open.

@antwerks has provided an excellent script for tracking this correlation:
https://usethinkscript.com/threads/market-sessions-vwap-asia-london-ny-am-ny-pm.22461/

What happens after the opening bell? Do you leave EXT on or toggle it off? The answer depends entirely on your timeframe, your indicators, and the time of day.

ToS calculates data based only on the candles visible on your screen. Toggling EXT completely changes their math. Because of this, the most effective approach isn't a permanent on or off switch—it’s a dynamic transition throughout the session.

Here is exactly how to manage your charts as the day unfolds:

1. The Open to 11:00 AM (Opening Range)
Lower Timeframes (1m to 1hr) & Tick Charts: Keep EXT ON.
Leaving EXT on early in the day prevents that gap blindness. A massive gap up on a Regular Trading Hours (RTH) chart looks like empty space. With EXT on, you can actually see the overnight price action, support/resistance levels. It gives you a continuous, unbroken roadmap for the open.

2. The Midday Switch (After 11:00 AM)
Lower Timeframes (1m to 10m) & Tick Charts: Switch to RTH.
By 11:00 AM, the opening range is set and the gap blindness is gone.
Switching to RTH cleans up your lowest timeframes.
It ensures your fast indicators are calculating purely against the high-volume, highly distinct price action of the current US session, removing the thin overnight noise.

3. Managing Mid-Timeframes (15m to 2hr Charts)
Through the Lunch Lull: Leave EXT ON.

Most traders use these mid-tier timeframes to track broader trends, market cycles, and phases. These macro structures are best viewed when all data is available, keeping the continuous overnight context intact while the morning volume dies down.​

Coming into the 1:00 PM Auctions: Switch to RTH.

If afternoons into Power Hour continue to post new highs; as seen this earnings cycle; you need to see pure volume action. Volume is notoriously difficult to track accurately with EXT on because overnight data dilutes the volume pool. Toggling to RTH ahead of the afternoon auctions gives you an undistorted view of institutional flow.​

4. Higher Timeframes (4hr and above)
For your higher timeframes, EXT does not pertain.
Always plot on RTH.


KEEP IN MIND:
Indicators calculate data based on the candles on your screen. Toggling ETH completely changes their math.
Using EXT during opening range allows you to use the data that resulted in the open's numbers.

But that thin overnight activity will skew your analysis as the current session progresses.
It is not applicable once you have accumulated enough current session bars to calculate current session price action and volume.
This is why you change over to the RTH after opening range for your lowest indicators and over to the RTH after lunch for the middle timeframe indicators.