In the following video, Fool markets analyst Mike Klesta talks with Fool contributor Dan Caplinger about the stock market's four-year rally to new record highs. Even though the Dow Jones Industrials (DJINDICES:^DJI) have gained 120% since March 2009, several stocks in the Dow have put in even more impressive performance over that timeframe.

Mike and Dan discuss the four best-performing stocks during the four-year bull market, explaining why they've done so well and evaluating whether they have the momentum to continue higher. Dan notes that out of these four impressive companies, one in particular has taken steps recently to further cement its industry dominance, making another in a long series of highly profitable acquisitions that should position the company to expand its business even further in the years to come.