stock performance graph the following graph compares the most recent five-year performance of the company 2019s common stock with ( 1 ) the standard & poor 2019s 500 ae index and ( 2 ) the standard & poor 2019s 500 ae materials index , a group of 25 companies categorized by standard & poor 2019s as active in the 201cmaterials 201d market sector . the graph assumes , in each case , an initial investment of $ 100 on december 31 , 2012 , and the reinvestment of dividends