Stock in Amazon.com fell 5% Tuesday after a Citigroup Smith Barney analyst Lanny Baker “slapped a sell rating on Amazon, citing new competition and the specter of higher technology and marketing costs.” Analysts are also wary of the fact that “By cutting prices and expanding free shipping offers, Amazon’s operating margins have declined.” But, according to a Business Week report by Rob Hof, another analyst thinks that “thanks to a number of developments not universally recognized by Wall Street, Amazon may well surprise the bears in months and years to come.” Says Bear Stearns analyst Robert S. Peck, “Most of the Street is pretty negative. We think they’re asleep at the wheel.” Peck thinks Amazons growth rate is underrated, and he thinks its “third party” sales—whereby other companies such as Target sell things on Amazon’s site—are going to do more for the company than expected because it’s got higher margins of profitability.