How to - Cleanup Bad Tickers

I have removed bad tickers from my TLS file but they come back. How do I permanently remove them?

For example, I have removed the extraneous watchlist from my .TLS file, but it still shows up in the download. (I did click refresh, and I did try to reload the .tls file from Amiquote). When I click the green arrow, the bad tickers come back.

There is a Amiquote FAQ on what to do if data are wrong, but I did not see any information on removing bad tickers (beyond removing them from the ticker list.

badtickers

Check out database purify tool

2 Likes

@codejunkie Thank you. The Database Purify tool works. I did not realize that AMIQuote looked at the Database (in addition to the .TLS) file to download data. As a side note, I noticed that some of my download errors occurred due to companies being delisted (but their historical information does remain.) So as a side note, it is important to examine each ticker (on a chart) to ensure you really want to delete it.

Hi Codejunkie, I ran through the process you describe. Before deleting the symbols, I clicked on some of them. Many had charts and seemed to have recent quotes.
image

Using the "Purify" list seems to be unreliable (deletes too much). I have tried looking at all results of the Purify-> missing quotes
and the subset of "No quotes" in the description field.

Is there a way to delete only the ones that fail to download in Amiquote? I can't seem to export just the selected tickers as a list.
My process in Amiquote so far:
Run a full auto-update
Select the failed tickers
Mark Selected
unable to export

It would be nice if Amiquote maintained an end date for each ticker so it would not attempt downloads after a certain date, but would keep the historical data. (avoiding some survivorship bias on backtests and improving update speeds significantly)

Running AB 6.20 and AQ 3.3

-Thanks

Looks like I figured out a possible solution to deleting only the failed tickers:
Warning: Be careful of the date range selected. An auto update will select dates only since the last run, which may cause more failures than pulling a full history.
i.e. Date range from 6/29/2018 to 6/30/2018 produces more failures than when using date range of
1/1/1970 to 6/39/2018
Warning: This will remove any historic data for those tickers, so I still believe having a flag/date in each database of the last valid date of each currently invalid symbol would be better.

Amiquote:

  1. run a full/auto update
  2. Select the "completed" tickets (Edit -> Select Completed)
  3. Edit -> Mark Selection (optional)
  4. Edit -> Delete tickers
  5. File -> Save As ("failed_tickers.tls)

Amibroker:
Symbols -> select a watchlist -> Right-click -> Import
Import the TLS file
Click on a ticker in the new watchlist
CTRL-A to select all tickers
Right-click on any of the selected tickers -> Delete

Results:
from a database of 8700 tickers
I believe I had about 4500 "missing quotes" tickers using the Purify tool.
...About 1800 "no quotes" tickers from the Purify tool.
...About 360 tickers using Amiquote failures process described here.

Please post if there is a better way or if there is something incorrect above,
-Thanks

4 Likes

Thanks! I have try it and seems to work but..
What about the tickers which have only 1 bar? I am trying to sort the list in amiquote by size but I cannot.

For example, Amiquote downloads the ticker LO3.DE (Only 1 bar) but I cannot find it in yahoo finance.

Thanks