It sounds like you are downloading daily date and then historical data on the weekends. Right? If so, the downloaders that I am familiar overwrite daily data when downloading historical data. This does not require deleting data although this should not be more difficult than highlighting all symbols in a folder and deleting all data at one shot. If yours does not operate in this manner consider getting another downloader. However, for non-index symbols you might want to do this in order to keep the data synched with dividend distributions, etc. which adjust data back to the first date.
As for differences in volume, you are probably seeing a total volume number that includes after-hours trading, as opposed to an error (you have to know what you data supplier is supplying). You can check this by comparing symbols that do and do not trade after hours. You can also check the data against some of the major charting websites such as Stockcharts.com. I don't think that you will find a difference. Bill ----- Original Message ----- From: patsgreatdeals To: [email protected] Sent: Wednesday, July 16, 2008 8:52 PM Subject: [amibroker] Volume Data from Yahoo! and Reloading Prior Week I have noticed when downloading quotes from Yahoo! the volume the day of the market close (regardless of the time you download it) is wrong. I end up each weekend deleting all the qoute data in various indexes, but not symbols. Who has time for that? Then download the past week again. Questions... 1. How can I download the prior weeks data and get the current volume in AMIBroker without deleting all the quotes of the last week? If I do not the vol does not change. 2. Does anyone have this volume issue with Yahoo! ? and if so did you end up just tossing in the towel and purchasing a data feed? ------------------------------------ Please note that this group is for discussion between users only. To get support from AmiBroker please send an e-mail directly to SUPPORT {at} amibroker.com For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: http://www.amibroker.com/devlog/ For other support material please check also: http://www.amibroker.com/support.html Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.138 / Virus Database: 270.5.0/1556 - Release Date: 7/16/2008 4:56 PM
