Fast-Growing Stocks to Buy: Valero Energy (VLO) Source: Mike Mozart via Flickr Valero Energy Corporation (NYSE: VLO ) is one of the top refiners in the U.S. For the past nearly 10 years, the Federal Reserve and all the central banks in all the industrialized nations have been managing interest rates to keep them outrageously low until the financial system had a chance to right itself. Economies are coming back online and central banks are starting to raise interest rates to keep inflation a bay while not shutting off the green shoots of growth.