Tesla is set to join the S&P 500 index of companies in December, a move which saw the firm's stock price surge in Monday trading as new investors and funds that track the index were tipped into buying.

A run of profitable quarters for Tesla was thought to have swayed the S&P 500's committee to grant admission to the over USD425bn (latest market cap) firm. It will be the largest firm ever added to the index.

The S&P 500 index is used as a representation of the market and is closely followed by major investment funds. Analysts say making the S&P 500 is a positive for Tesla and its image, reinforcing its position as an established company rather than as a risky one subject to tech sector volatility.

Media reports suggest the recent surge in Tesla's value will boost Tesla founder Elon Musk's net worth by more than USD15bn to around USD117.5bn. That would make Musk the world's third richest person - now ahead of Mark Zucherberg, but behind Bill Gates and Jeff Bezos.