Google's ( GOOG) tremendous run from its August 2004 initial public offering to its standing as a tech giant with a $100 billion market cap has finally been recognized by the overseers of the S&P 500. Standard & Poor's, after passing up earlier opportunities to add Google to the index, said Thursday that the Internet-search company will replace Burlington Resources ( BR) in the S&P 500 after the close of trading March 31. Google's shares surged $25.09, or 7.3%, to $366.98 in after-hours trading. Google's addition will create demand for its shares because mutual funds whose composition allow them to track the S&P 500 will have to buy the stock. Burlington Resources is being removed because it's getting acquired by ConocoPhillips ( COP). Google had been passed over in recent months for the likes of cosmetics maker Estee Lauder ( EL) and pricey supermarket chain Whole Foods ( WFMI), irking tech investors who had been hoping the Mountain View, Calif., company would get the call. Some analysts, including Bear Stearns' Robert Peck, had expected Google to eventually be added to the index. "For Google, we estimate demand of about 20 million shares from index funds, which represents about 1.5 days of volume and roughly 7% of Google shares outstanding," Peck wrote in a research report in February, when the company had a market cap of around $120 billion. Google's addition to the S&P comes at a time when the shares are about 28% below their 52-week high of $475.11. The stock's low for the past year is $177.64.