Here are the stocks making notable moves in midday trading.
Tesla – The automaker rose 1.6% to a new all-time high. The move caps a record year for Tesla, which saw the company report five straight quarters of profit extending back to 2019. The electric automaker was also added to the S&P 500. Shares are up more than 750% for the year.
Enphase Energy – Shares gained 1.5% slightly after S&P Dow Jones Indices said the Australia-based energy technology company will replace Tiffany in the S&P 500 benchmark as of Jan. 7. Tiffany is being acquired by LVMH. Enphase Energy's stock has soared more than 560% this year amid heightened interest in solar energy.
Western Digital – The stock jumped more than 11% as investors piled into the chipmaker into the end of the year. Western Digital has gained more than 21% this month alone, cutting its 2020 losses to about 13%.
Tribune Publishing Company — Shares of the Chicago Tribune and New York Daily News owner jumped more than 7% after a securities filing showed that Alden Global Capital made a non-binding offer to buy the company. Alden is already a major shareholder in Tribune, owning roughly 32% of the company's outstanding stock. The Wall Street Journal first reported the news.
Celsius Holdings — Shares of the beverage company soared more than 13% after S&P Dow Jones Indices announced that the stock would join the S&P SmallCap 600. The change will be effective Jan. 7.
— CNBC's Pippa Stevens and Yun Li contributed to this story.