Oftentimes, portfolio performance can benefit from lack of action. In other words, investors may be better off simply leaving their stocks alone, and not worrying about timing the market to buy and sell at the right times.

 

"We continue to make more money when snoring than when active," famed investor Warren Buffett has said. On a similar note, he has said, "Our favorite holding period is forever."

 

With this important investment principle in mind, here are three stocks in our portfolio we almost certainly won't be selling in 2017: Tesla Motors, Facebook and Apple.