SP Global has confirmed that Tesla will be added to the index prior to the open of trading on December 21.
Tesla, whose stock closed at $408.09, surged about 14% at 6:20 p.m.in NY, lifting Musk's net worth to $117.5 billion, according to the Bloomberg Billionaires Index.
The announcement, made Monday afternoon by the S&P Dow Jones Indices, sent shares 13.7% higher in after-market trading.
Tesla turned its fifth straight quarterly profit last month at 76 cents per share, ahead of the 57-cents-per-share estimate, while year-over-year total revenues increased 39% to $8.77 billion.
Tesla stock has increased fivefold in 2020 on the strength of numerous developments: from introducing the Model Y, the crossover variant of the Model 3 that became the world's most successful electric vehicle, to gigafactories opening, under construction or announced on three continents, and to bouncing back from the Covid-19 pandemic to post a record third quarter including a net income of $US809 million ($A1.1 billion).
The company, led by Elon Musk, has a market value of $386.83 billion as of Monday's close.
The world's most valuable auto company, Tesla, is set to join the S&P 500 in December.
With a stock market value over $400 billion, Tesla is larger than the vast majority of the companies already in the index.
Shares in Tesla soared by as much as 14pc after the company joined the prestigious ranks of the S&P 500 list.
Tesla's inclusion in the widely followed stock market index means investment funds indexed to the S&P 500 will have to sell about $51bn worth of shares of companies already in the S&P 500 and use that money to buy shares of Tesla, so that their portfolios correctly reflect the index, according to S&P Dow Jones Indices.