Apple stock is at its highest since January.
The stock topped $500-dollars Wednesday.
Some private investors are buying into the stock, calling it undervalued.
Businessman and investor Carl Icahn says if apple would use some of its cash to buy own stock, the value could approach $700.
This target is beyond the highest wall street estimate of $655.
Copyright 2013 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.