When comparing the 30 minute timeframe on any stock in TC2000 to the same timeframe/stock in ThinkorSwim the 200SMA is way off. How can this be so different? I'm not talking pennies here. This makes me not trust the moving average now. 

Humm, the quiestion is which one NOT to trust.  I know i sometimes mention to friends on other platforms a PIVOT line like R2 for example and the IB or TOS are different.  I have used most and find the Math and calculation by TC2000 to on the money. 

I would first check EMA vs SMA settings on both platforms

Thanks for the reply. I have checked the settings. Both are SMA that I am using. I do know that TC2000 doesn't include premarket or after hours price action (at least I haven't figured out how to view it other than the current trading day). SO perhaps that affects the math?

For example, on $IBB this morning.; TOS tells me on the 30 min chart the 200SMA is at 286.79. On TC2000,  its at 284. A big difference. Same time frame, same setting. 

That would in fact affect the math if the TOS moving average is including the pre and post market data and TC2000 is not (or vice versa). If you have RT data in TC2000, you should be able to right-click on the chart and select Edit Chart Properties | Pre/Post Data to turn the pre and post market data on for a chart.

How to view Pre- and Post-market data

That said, there are lots of other reasons for the moving averages to be off. If you have already verified the moving average settings, my best guess at why the moving averages would be different is that one of the moving averages is applied to price while the other moving average is applied to something else (such as another moving average).

Try removing and re-adding the moving average. Make sure you select price when prompted as to the parent indicator to which you are adding the moving average.

I've also checked with a freind who uses ScotTrade. His 200SMA lines up with my TOS. TC2000 is off by a couple dollars. Very strange.

I have my pre/post data on. It only shows for the current day correct?

I've made sure to apply all the correct settings. It's just off.

What is the name of the layout and chart in TC2000 where this is happening so I can take a look?

RyanSept2016

Note that I can't actually look at your software to make a comparison. I can just look at your settings in our program to see if the settings appear to be correct.

I don't see any 30 minute charts in that layout tab. All of the 200 period moving averages on the charts in that layout tab appear to be of price. All but one (which is front weighted) of the 200 period moving averages on the charts in that layout tab appear to be simple.

We do only carry two sessions of pre and post market data. So we carry the current session plus one session back. If your other services carry more than this, it would definitely affect a 200 period moving average in a 30 minute time frame.

The other thing which could affect this is that we only plot bars for pre and post markets if there was a trade during that bar. This is different that during the trading day where we would plot a bar for each time interval even if there aren't any trades.

If the other software does either any of these things differently, then that would affect the moving averages as well.

Try adding 200 period Linear Regression Lines to both programs. This should stretch back 200 bars. Is the time and date covered by those 200 bars the same? If not, that is what is causing the issue (be it from number over sessions covered, how overnight bars are plotted or how regular session bars are plotted).

Also look at the bars that are plotted. Are the bars the same? Could there be a split or dividend which is adjusted for in one program but not the other (we adjust for splits and fund distriubtions but not stock dividends).

I am noticing a similar difference between the the 50 EMA on TC2000 and TOS on the 10m timeframe and dramatically on the 1hr timeframe.   I notice that TC2000 only gives me today's pre/post market data nothing before. (I did change the settings.  Saved and restarted the program).  (As of today 8/29/2018, examples are $NFLX, $BOOT and $DSW)  They are different on those tickers for some reason.   I have checked my settings in both platforms:  

I have pre/post market data turned on to "always" (both platforms)   

I have it set to "last" for TC2000 and "close" on TOS.   Any help would be appreciated!   Thanks!

On the one hour time frame, part of the difference could be if their hours start and stop at the bottom of the hour. Our hours start and stop at the top of the hour.

Also not that an hourly time frame is usually going to cover way more than two pre / post market sessions (which is all that is available in TC2000).

The 10 minute time frame also usually going to cover more than two pre / post market sessions.

Each time frame also starts the day with the most recent 500 bars of data available and adds new bars through the day if applicable. So if 500 bars is not enough to get you to a particular pre / post market session, it isn't going to display even if it would be one of the two most recent sessions.

Thanks Bruce for the prompt follow up.   

I guess my question is:  Why does TC2000 feel it only needs to provide the past 24 hours for pre/post market data?   If you have previously plotted the data for the latest 24 hour periord why not just make it historical and give an option to see/use it?   

Every other service allows this and plots the data if turned on (Obviously I am assuming just because I can't see previous premarket and post market data that it may not be used which may not be the case.)   So every other trader is using that information to trade which could put your users at a disadvantage on intraday timeframes if that data is not being accounted for outside of regular trading hours.  

Please advise if the data is unseen but still used.  Thanks.

I really can't answer why type questions. I can tell you the way things work, but not why.

Thank you for your suggestion.