As the markets continue ever upwards, many investors are getting nervous that a major market pullback is not far off. Is this a market bubble, and should we be preparing for it to burst? In the video below, Fool contributor John Reeves takes a look at some analysts' opinions on whether or not we are experiencing a bubble at the moment, and he discusses some of the stocks contributing to these all-time market highs. Finally, John tells investors how to play today's dizzying market highs the Foolish way: by investing for the long term.