Apple (AAPL -3.6%) has sold off in early trading, apparently on news clearing firms are raising...

|About: Apple Inc. (AAPL)|By:, SA News Editor

Apple (AAPL -3.6%) has sold off in early trading, apparently on news clearing firms are raising their margin requirements for positions due to fears of being too heavily concentrated in the $526B company. One firm, COR Clearing, raised its margin requirement to 60% from 30%.