Stocks have needed a reason to take a breather and pull back in this long-standing ultra-bullish climate, with strong economic data and seasonality providing impressive tailwinds -- and plummeting oil prices certainly have given it to them. But this minor pullback was fully expected and indeed desirable for market health. The future remains bright for the U.S.

Last week, I talked about the impressive strength this year in the Dow Jones Transportation Average, but it since has been hit by investors’ renewed worries about global economic growth and financial stability. Its fall has been led by weakness in the airlines.