Apple has a hidden business that's bigger than some airlines (AAPL)

Apple CEO Tim Cook said that its "wearables" business is as big as a "Fortune 400" company, implying that it does at least $6.7 billion in annual sales. Apple considers "wearables" to be its Apple Watch, Beats headphones, and AirPods earbuds.  Apple is known as the iPhone company, because that iconic product drives over half of its sales.  But Apple CEO Tim Cook dropped hints on Thursday that the company has a new line of products that's flying under the radar and growing...