I want to analyze data with Amibroker but I am surprised by the difference between data sources . Example: AI (Air liquide - Paris) on the 06-06-2008 have a closing price of : 93.03 with yahoo 93.03 with Google 81.65 with prorealtime 84.57 with IB 84.57 with boursorama Which source is the most reliable and why such difference??
Of those sources, IB is the reliable one for data, although they post aggregate data and not real tick data. What is the timestamp for each of those data sources? A closing price could mean lots of things.
Thanks for your prompt answer. They are EOD datas so I don't have the time stamp. Is there an "official" closing price that can be downloaded somewhere?
The differences I mentioned are not only on the close price but are there several days before. I would be very grateful if somebody having experience with many data sources could have a look and give an explanation. Thanks in advance
Prices are from : IB for AI-SBF Yahoo Finance AI.PA Google EPA:AI Prorealtime free eod data : AI Borsorama : AI So I think all from same market (Euronext Paris)