On April 7, 2008. Apple (AAPL) was up 2.81 to 155.89 after it was upgraded by Thomas Weisel from "Market Weight" to "Overweight".
The next day which is on April 8, 2008. Apple (AAPL) was downgraded by Morgan Keegan from "Marker Perform" to "Under Perform" and Apple was down 3.05 to 152.84.
This is not the first time Analysts have mixed opinions about Apple. On January 23, 2008. Needham & Co has upgraded Apple from "Buy" to "Strong Buy" but Caris & Company has downgraded Apple from "Buy" to "Above Average". It is really amusing to see such a thing happened. The bottom line is analysts can not be trusted and there might be some hidden agenda for upgrading or downgrading the company (eg: downgrade as the company is holding short position or vice versa)