BlackRock Inc, the world’s largest money manager, will be added to the Standard & Poor’s 500 Index, S&P said in a release on Tuesday.

New York-based BlackRock will replace Genzyme, which is being acquired by Sanofi-Aventis, after the close of trading on April 1, S&P said.

Though it went public in 1999, BlackRock only became eligible to be included in the index in November when more than half of its shares became publicly traded.

Shares of BlackRock jumped 6.2 percent to $198 in after-hours trading after closing at $186.50 in the regular session on Tuesday. Funds with about $1.25 trillion under management track the S&P 500 index and will have to add BlackRock shares.