Tesla will join the S&P 500 on December 21, S&P Dow Jones Indices announced Monday.
With a market cap of nearly $400 billion, Tesla joins as one of the 10 most valuable companies in the index.
S&P Global did not say which company Tesla will replace later this year.
Shares of the electric-vehicle manufacturer jumped more than 13% on the news in after-hours trading.
The S&P 500 is an index of 500 large US companies, says Business Insider.
It is seen as one of the most important gauges of the success of America's largest publicly-traded firms.
