Shares of Tesla dropped nearly 7% in extended trade on Friday after the electric car maker was excluded from a list of companies being added to the S&P 500.

The decision by S&P Dow Jones Indices is a blow to Tesla investors who widely expected the company to join the benchmark stock index after a blockbuster quarterly report in July cleared a major hurdle for its potential inclusion.

S&P Dow Jones Indices said in statement it was adding online craft seller Etsy, semiconductor equipment maker Teradyne and pharmaceutical technology company Catalent to the S&P 500, effective Sept. 21, and removing H&R Block, Coty and Kohls.

Shares of Etsy jumped 6% in extended trade, Teradyne rose 2%, and Catalent added 2%.

With a market capitalization over $300 billion, Tesla is one of the most valuable companies on Wall Street, and by far the most valuable publicly listed U.S. company not included in the S&P 500.

Due to its large stock market value, adding Tesla to the S&P 500 would trigger massive demand for its shares because index funds that track the benchmark would have to bring their portfolios into line.