Shares of Apple (NASDAQ:AAPL) fell more than 3 percent on Tuesday, but are relatively flat in late afternoon trading. The tech giant finished the day at 11-month lows and closed below $500 for the first time since February. Rumors continue to swirl about more iPhone models hitting the market. Peter Misek from Jefferies wrote in a note to investors that two prototypes already being tested by Apple include an iPhone 5S and a low-cost version of the iPhone. While the 5S would be just an incremental upgrade to last October’s iPhone 5, a low-cost phone targeted toward emerging markets had also received the green light.