(Reuters) – Shares of Super Micro Computer rallied 13.5% in extended trade on Friday after it was announced the seller of AI-optimized servers will join the S&P 500.

Super Micro and Deckers Outdoor Corp will be added to the S&P 500 prior to the start of trading on Monday, March 18, coinciding with a quarterly rebalance of Wall Street’s most widely followed stock benchmark, S&P Dow Jones Indices said in a news release.

Those two companies will replace Whirlpool Corp and Zion Bancorporation, S&P Dow Jones Indices said.

Index funds that track the S&P 500 are among the most popular investment tools on Wall Street, and those funds will have to purchase shares of Super Micro and Deckers in order to stay aligned with the benchmark’s composition.

Such S&P 500 index funds have assets of about $7.8 trillion, according to Howard Silverblatt, Senior Index Analyst at S&P Dow Jones Indices.

Super Micro sells high-end servers made with Nvidia’s top-of-the-line AI processors, and its stock has more than tripled this year.

With Super Micro’s stock market value reaching over $50 billion, investors had speculated the company would be added to the S&P 500.

On Friday, investors exchanged almost $10 billion worth of Super Micro’s shares, eclipsing trading in Wall Street heavyweights including Microsoft and Amazon.

Its jump in after-hours trading adds to a 4.5% surge during Friday’s trading session.

Shares of Deckers rose 2.7% in extended trade, while Whirlpool dipped 1.7% and Zion Bancorporation fell 2%.

(Reporting by Noel Randewich; editing by Diane Craft)