The Globe and Mail reports in its Thursday edition that the U.S. Securities and Exchange Commission has sent subpoenas to Tesla regarding chief executive officer Elon Musk's plan to take the company private and his statement that funding was "secured." A Reuters dispatch to The Globe says that after the Fox Business report Wednesday, the electric car maker's shares fell as much as 4 per cent, but cut its losses after Goldman Sachs said it was dropping equity coverage of Tesla because it is acting as a financial adviser on a matter related to the carmaker. Investors viewed the Goldman statement as confirming a tweet from Elon Musk on Monday about working with Goldman, even as the reported subpoenas indicated the SEC has opened a formal investigation into a matter. The latest news extended the roller-coaster ride for Tesla investors in recent days, adding to uncertainty about the future course of the company and whether a deal can be done amid growing regulatory complications. Mr. Musk stunned investors and sent Tesla's shares soaring 11 per cent when he tweeted early last week that he was considering taking Tesla private at $420 (U.S.) a share and that he had secured financing for the potential deal.