RadioShack is a company whose turnaround perpetually seems to be around the next corner, but it may not be the screaming buy it appears to be on paper. For one thing, its cash balance has dwindled while inventories have risen dramatically. That's partially driven by having more expensive items in inventory -- but those items not only carry low margins, but they also may have to be discounted if RadioShack has trouble selling them.

Considering that it couldn't sell the iPhone 4S, at the time the hottest consumer-electronics device in the world, when it was released, there isn't much to suggest this will be a competent mobile retailer in the future.

Instead, the best mobile company to buy today may very well be the one that's crushing RadioShack's margins: Apple.

On its way to becoming the world's largest company, Apple has delivered market-smashing returns for those lucky enough to have invested early. However, at these prices, maintaining that torrid pace will only get more difficult. If you're looking for a recommendation on how to play Apple along with continuing updates and guidance on the company whenever news breaks, we've created a brand-new report that details when to buy and sell Apple. To get started, just click here now.