Google enters the index / All eyes are on the Internet firm as it joins the S&P 500

Google enters the index / All eyes are on the Internet firm as it joins the S&P 500: "Google shares jumped 7 percent Friday in response to an announcement late Thursday that the Internet company will be added to the Standard & Poor's 500 index, effective next Friday."This "Index effect" has been well studied. Some argue it is liquidity, while others suggest it is an information story (more