Tesla Inc ( TSLA.O ) shares soared 17% on Thursday after the electric carmaker surprised Wall Street by delivering on Chief Executive Officer Elon Musk’s promise of a profit in the third quarter, even as doubts remained about its long-term prospects. Trading at $298, Tesla’s market capitalization was $53 billion, surpassing General Motors Co’s ( GM.N ) $51 billion stock market value and making it the United States’ most valuable car company. It has been the No. 1 U.S. car company by market cap before, but recently GM has had a substantial lead. Tesla late on Wednesday reported a quarterly profit, citing improvements in operating efficiency and a reduction in manufacturing and material costs. The strong report unleashed a bloodbath on traders shorting Tesla, the second most […]