Fidelity data gap around earnings and dividends
Author: Tobey
Creation Date: 12/23/2016 3:05 PM
profile picture

Tobey

#1
Hi Cone & Eugene,

Some times when I first open a chart their is a large gap around earnings and dividends. as in attached chartOpened.jpg

When I reload the data I get a different chart - DataReloaded.jpg. This also can often change the results of the strategy for that chart.

I'm using Fidelity Data. What's going on??

Merry Christmas
Tobey
profile picture

Eugene

#2
Hi Tobey,

Maybe your data is broken, or hard drive has become unreliable, or maybe... Who knows. Is TXRH the only stock and Fidelity the only provider affected by this issue?
profile picture

Tobey

#3
Hi Eugene,

This is not the only stock with the problem. It is also not the only date. What is consistent is that it is happening around earnings and dividend markers on the chart. Here is another example.

Thanks
Tobey

PS I think we can rule out hard drive problems because I have data on more than one computer.

profile picture

Cone

#4
It's not an uncommon problem, but we've never been able to catch why it happens. Occasionally you'll find that the provider data is missing a large number of bars for no reason. That's why I recommend that you run a "Bad Data History Check (Rev. A)" before doing serious backtesting. See the Description for instructions.

If the script identifies a missing bar or two (especially before 2001), you can ignore the warnings. It could be that the stock just didn't trade that day, or more likely, the data on the server is missing. Look for large sections of missing data, like in your example. The script will give you an option to delete the data so that you can easily refresh on the next update.

If you only need Nasdaq 100 and S&P 100 stocks for EOD testing, I highly recommend our own Wealth-Data.
profile picture

Eugene

#5
QUOTE:
That's why I recommend that you run a "Bad Data History Check (Rev. A)" before doing serious backtesting.

In addition to the utility script mentioned by Cone which you can get by clicking "Download..." in the "Open Strategy" dialog, you might want to use the Data Tool's similar data checker features in the Data Manager's GUI. Direct installation link: Data Tool.
profile picture

Tobey

#6
Hi Cone & Eugene,

I'll run them both and keep my eye on the results.

Thanks
Tobey