Image source: Getty Images.The Dow Jones Industrials (DJINDICES: ^DJI) reached new all-time highs on Tuesday, setting its first record in more than a year. Investors pointed to new optimism about the course of the stock market despite long-term concerns about macroeconomic conditions worldwide and the potential for geopolitical disruptions. Yet looking back over the past 14 months, you can see that out of the 19 stocks that have climbed since the previous May 2015 highs, three companies really stand out as having produced strong returns.