Amazon Takes New Plunge

Amazon (AMZN Quote) plunged 17% Wednesday as investors fled the e-tailer's costly free shipping plan.

Shares of the largest Internet retailer dropped $5.78 to $27.81, setting a three-year low. Wall Street sees the company's hefty spending and narrow margins as hoisting a red flag over the Seattle-based company.

Operating expenses in the latest quarter jumped 34% from a year ago to $464 million, led by gains in fulfillment, marketing and technology, the company said. Profit dropped 58% from a year earlier. After sending the stock down 11% in postclose action Tuesday, investors renewed their selling amid a flurry of negative research notes Wednesday morning. ...