TOS charts taking FOREVER to load

Just wanted to follow up with the solution here in case anyone ever encounters a similar problem. After weeks of back-and-forth with TOS reps and getting nowhere, I ended up figuring it out by myself. The lag was caused by my having the “adjust for dividends” box in my chart settings set to “All”.

Over the past couple of months I noticed that my charts were loading very slowly right after the bell and right before the close.  I contacted Schwab and got commiseration, but no real help.  Then I tried everything mentioned in this and other threads to troubleshoot my MacBook, adjusting memory, deleting watchlists, removing indicators, etc.  But then I noticed that I had the same problem with ToS charts on my iPhone.  That seemed to indicate that the problem wasn't necessarily at my end.

Another interesting observation was that not all of my charts were delayed.  The five-minute charts loaded right away, as did the weekly charts.  But my main view, the 2-hour chart, could take minutes to load -- for up to an hour after the bell!  How could some charts load while my 2-hour charts couldn't?

After some more research, I found this: a 2-hour (120-min) chart is a valid but less common aggregation in TOS; it exists in the platform’s docs, but it’s not a default most people use or that vendors heavily cache. That can mean more on-the-fly aggregation during peak load. US regular session hours are 390 minutes. 120 doesn’t divide evenly into 390 (390 ÷ 120 = 3.25), so each day ends with a partial bar. Partial bars get rebuilt constantly during high-traffic windows (open/close), which can exacerbate lag—whereas 65-min or 130-min bars “fit” perfectly (390/65=6, 390/130=3) and are cheaper to recompute.

So I tried loading a 65-minute chart, and it loaded immediately (while the 2-hour chart still wouldn't load).  Same thing with a 130-minute chart.  Using this duration, the charts load rapidly.  While I'm not planning to start using the 130-minute chart as my standard, in early trading when I need to run through a lot of charts quickly, I'll use the 130-minute duration.  If I see something that might be actionable, I'll switch back to 2-hour and wait the 1-2 minutes for it to load to verify what I saw on the 130-minute chart.  About an hour into the session, I'll switch back completely to the 2-hour duration.

This has been a daily irritation for me.  Since I found what I think is a decent workaround, I thought I'd share it with the community.

Only three things left I can think of. However I will say the most likely culprit is the data feed from the Thinkorswim servers. They are very well known to be heavily impacted by high market volume. Which is the norm during market open and close.

1. When experiencing this problem, close all watchlsits. Each stock ticker in a watchlist is an additional load on the Thinkorswim server. In your screenshot I see four separate watchlists. And some of those may contain custom columns, or other code that increases the load further. So try creating a personal watchlist that contains only one stock ticker. Then set all your watclist gadgets to that one-ticker watchlist. Then check the load time of the chart by manually typing several stock tickers and see if things have improved.
2. What version of Java do you have installed? Attached screenshots show the System Preferences and the Java console. You should have at least JRE 8 installed. With the latest updated applied. I recently removed JRE 8 and manually installed JRE 10 to make sure my system has the most advanced Java Runtime Environment.
3. Your antivirus software may be causing the problem. (if you have one installed). Check the settings of the antivirus software to make sure it is not blocking or restricting traffic to the Thinkorswim servers. Depending on the software, there may be a way to set a rule that excludes traffic to Thinkorswim servers from any real-time scans.

That’s all I’ve got. I can certainly attest to the fact that Thinkorswim has a problem during high market volume. Always has. And I expect it always will. If this problem is preventing you from being a profitable trader you should consider moving to a more advanced trading platform. Most will require Windows to run. But you can run that via Bootcamp or via a Virtual Machine. (I personally use Parallels for my VM). Works excellent and I use it to run TradeStation and Sierra Chart. Hope I was able to provide some help.

I had the similar problem in the Windows PC but the problem was due to high ping from the internet and restarting a router solves my problem when this happens. Based on Pete's solution I learnt that I need to have Java installed which I don't have it too. I was wondering that Java is required in Windows PC.