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Hello,
Thank you for the notice.
Please send such stuff directly to me otherwise I may overlook such
important post among hundreds of others.
I will adapt AmiQuote shortly to address this change in Yahoo service.
Please note that you can adjust prices in AMiBroker
using Symbol->Split tool. And you can detect places where possible
splits are using Tools->Database Purify.
(I agree this is a big task if you have thousands of stocks)
Best regards,
Tomasz Janeczko
amibroker.com
----- Original Message -----
From: "b519b" <b519b@xxxxxxxxx>
To: <amibroker@xxxxxxxxxxxxxxx>
Sent: Friday, September 12, 2003 9:17 AM
Subject: [amibroker] Alert - AmiQuote Update Needed - (for Tomasz)
> Tomasz,
>
> I just discovered that Yahoo has changed what they put in their csv
> download quotations. To see this, do a fresh download of QQQ's
> entire history - there is a $111 price discontinuity on March 20,
> 2000 due to the 2:1 split on that day. That discontinuity will mess
> up indictors, stop triggers and profit/loss calculations.
>
> In the past Yahoo's csv file had OHLCV using split adjusted figures
> (and no figure for non-adjusted, ie pre-split, prices).
>
> But now Yahoo's csv download files have OHLC in NON-adjusted prices,
> then Volume, then the ADJUSTED price for the close. Now the download
> csv file matches the Web Table format Yahoo has long used.
>
> May I suggest that AmiQuote be upgraded to do the following:
>
> 1. Put the non-adjusted close price into the AB's OI field (after
> being multiplied by 100 to preserve the decimals). This is a very
> valuable new piece of data.
>
> 2. Use the ratio of non-adjusted close and adjusted close to
> calculate adjusted prices for OHL and put adjusted prices into the
> OHLC fields in AB's database. That will solve the price
> discontinuity problems.
>
> This change by Yahoo is a tremendous "gift". Most data providers do
> not give users any way to get the non-adjusted closing price. That
> price is what should be used in any price filter. Using adjusted
> prices in filters introduces subtle but potentially costly
> distortions into back tests.
>
> b
>
>
>
>
>
> Send BUG REPORTS to bugs@xxxxxxxxxxxxx
> Send SUGGESTIONS to suggest@xxxxxxxxxxxxx
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>
>
>
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Send SUGGESTIONS to suggest@xxxxxxxxxxxxx
-----------------------------------------
Post AmiQuote-related messages ONLY to: amiquote@xxxxxxxxxxxxxxx
(Web page: http://groups.yahoo.com/group/amiquote/messages/)
--------------------------------------------
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