Yahoo! Inc has taken yet another step into the big league as the company’s stock will be added to the venerable S&P 500 index as of the close of trading on Tuesday, December 7. Yahoo replaces consumer automotive manufacturer Laidlaw Inc in the index and will become part of the computer software and services industry group. Based on Tuesday’s closing price of $212.75, Santa Clara, California-based Yahoo has a market capitalization of $56bn.

After the announcement was made late Tuesday, Yahoo shares jumped more than $22 in after-hours trading, according to Instinet Corp. During the normal trading session the stock had lost $13.375 on the Nasdaq. Inclusion in the S&P 500 usually leads to increased demand for a company’s shares because fund managers who want to match the performance of the closely-watched index must buy into the stock.