Portfolio123 - View Thread - Discrepancies in Screener tool ?

Home Ready-2-Go Portfolio Ranking Screener Stock ETF Tools Community Help

Forums Email User Polls Feature Requests Groups

Index | Recent Threads | Who's Online | User List | Search

Portfolio123 » List all forums » Forum: Data related issues » Thread: Discrepancies in Screener tool ?

Thread Status: Normal
Total posts in this thread: 7

[Request a Feature] [Post new Thread]
[Add To My Favorites] [Watch this Thread]

Author

This topic has been viewed 1010 times and has 6 replies

cad
Member

UNITED STATES
Joined: Nov 8, 2006
Posts: 9
Status: Offline

Discrepancies in Screener tool ?

Reply to this Post
Reply with Quote

Marco / All

Quick question on the screener tool -

Is it correct to assume that if I run a screener today (1/21, Sunday), that the screener will output recommendations with the latest refresh of data from yesterday, 1/20, for trade tommorow? If that's the case, when I run the screener backtest option, the results are based on MONDAY's screener output rather than Sundays, and often the screener recommendations are different on Monday than Sun. Can someone help explain this discrepancy?

Thanks so much!

[Jan 21, 2007 4:39:17 PM]

[Link]

marco

UNITED STATES
Joined: Jan 1, 1970
Posts: 4050
Status: Offline

Re: Discrepancies in Screener tool ?

Reply to this Post
Reply with Quote

An example would help immensely. Thank you
----------------------------------------
Portfolio123 Staff

[Jan 22, 2007 2:12:55 PM]

[Link]

cad
Member

UNITED STATES
Joined: Nov 8, 2006
Posts: 9
Status: Offline

Re: Discrepancies in Screener tool ?

Reply to this Post
Reply with Quote

Here's an example:

When I ran one of my screeners on 1/28, Sunday, I got the following picks: MEH, MALL, ACET. I ran the screener the following day to see if the picks would change, and it remained the same, which it should. However, when I run the backtest function, I get the following picks: TESS, MEH, MALL. Why is this the case? This significantly impacts returns.

Thanks.

[Feb 27, 2007 9:27:45 AM]

[Link]

marco

UNITED STATES
Joined: Jan 1, 1970
Posts: 4050
Status: Offline

Re: Discrepancies in Screener tool ?

Reply to this Post
Reply with Quote

Which screen so I can test. Thanks.
----------------------------------------
Portfolio123 Staff

[Feb 27, 2007 9:35:00 AM]

[Link]

cad
Member

UNITED STATES
Joined: Nov 8, 2006
Posts: 9
Status: Offline

Re: Discrepancies in Screener tool ?

Reply to this Post
Reply with Quote

Filip_v9

[Feb 27, 2007 9:42:18 AM]

[Link]

marco

UNITED STATES
Joined: Jan 1, 1970
Posts: 4050
Status: Offline

Re: Discrepancies in Screener tool ?

Reply to this Post
Reply with Quote

The screen backtest uses the next day prices, the historical previous da closes. An option should be added to the screen backtest to chose which prices to use, like the portfolio simulation: prev day close, next day open or avg of hi+lo, for example.
----------------------------------------
Portfolio123 Staff

[Feb 27, 2007 10:55:29 AM]

[Link]

Stittsville123
Advanced Member

CANADA
Joined: Nov 20, 2004
Posts: 1347
Status: Offline

Re: Discrepancies in Screener tool ?

Reply to this Post
Reply with Quote

Marco - is the backtest screener ranking based on next day prices? It should be based on previous close. Only performance should use next day prices.

[Feb 27, 2007 11:53:16 AM]

[Link]

[Show Thread Printable Version] [Post new Thread]

Free Trial / Log In