A benchmark index, used to track the fortunes of the semiconductor industry, that was created by and is traded on the Philadelphia Stock Exchange. The SOX is a price-weighted index composed of 17 U.S. companies primarily involved in the design, distribution, manufacture, and sale of semiconductors. The index was set to an initial value of 200 on December 1, 1993 and was split two-for-one on July 24, 1995. Options began trading on September 7, 1994.