(AMZN) - Get Report

was down 10.8% in preopen


trading after

Prudential Securities

downgraded it from hold to sell.

Analyst Mark Rowen said the online retailer has shown weak growth in its book, music and video business. In a research note, Rowen said he believes that in a best-case scenario the stock is worth $62, but he cut his price target to $9 from $20.