When Tesla officially joins the S&P 500 on Monday, Elon Musk's electric car company will instantly become the top performing stock in the index for 2020. Shares of Tesla (TSLA) are up nearly 700% so far this year, more than double 2020's current top performer on the index. The stock has surged almost 65% since the mid-November announcement of its S&P 500 inclusion. The second best performing stock in the S&P 500 this year is also a recent addition. E-commerce firm Etsy (ETSY), which joined the index in September, is up about 325% for the year. Carrier Group, a spinoff of United Technologies following that company's merger with Raytheon, is up about 225%. Chip giants Nvidia (NVDA) and AMD (AMD), PayPal (PYPL) and Bath & Body Works and Victoria's Secret owner L Brands (LB) have all more than doubled this year too.