After months of speculation, car manufacturing startup Tesla is...<br />...Becoming the newest addition to the S&P Dow Jones Indices on December 21st.<br />The value of Tesla’s shares jumped more than 10% in the after-hours session on Monday.<br />The jump is directly related to and in response to the news, according to Gizmodo.<br />Investors have guesed the electric vehicle pioneer would soon find its way to the index.<br />This paves the way for the company’s current market valuation of more than $380 billion.