The Standard & Poor's 500 will soon contain 505 listed stocks, up from the current 502 listed stocks.
S&P Dow Jones Indices, which oversees the benchmark index of large U.S. stocks, on Monday announced a methodology change that will cause three more companies to have multiple listings: Comcast, News Corp., and 21st Century Fox. (Disclosure: Comcast is the parent of NBCUniversal and CNBC.)
The change follows a move made in January to allow multiple share classes in S&P indexes. It will take effect after the close of trading on Sept. 18, to coincide with a quarterly rebalancing.