ASML Holding (ASML 1.79%) is an unsung hero in the semiconductor industry. It builds lithography machines, which project ultraviolet light onto silicon to make advanced chips. Playing that crucial part has propelled the stock to strong investment returns over the years. The company has split its stock before, but 2007 was the last time. Since then, shares are up more than 1,500%. Trading at over $700 per share, the stock has become more challenging for individual investors to swallow. So should investors lo ...