newbie so apologies for the basic question.
I am running zipline on my local machine and compare it with the result on Quantopian backtesting. Then I realized that the stock price differs between ( I am quite sure I am using the same time)
For example. AAPL price on Jan 7th 2013 was 70.30, but the web page shows 74.85 !!
The code are exactly the same, the only difference is
one is programmatically seting the start/end time, the other is to use Quantipian's UI to set time.
Really confused about that.