Shares of Tesla tumbled as much as 8.9 percent Friday after a New York Times feature outlined some serious struggles for CEO Elon Musk. The electric car maker's stock was on pace for its worst day since March 27, when the stock fell 8.22 percent. Shares, which were down 7.6 percent late in the morning, lost 12 percent over the last year and have been especially pummeled in the last week. Tesla has fallen more than 15 percent since Musk tweeted last week that he was considering taking Tesla private. The SEC began an investigation after the tweet and has reportedly sent out subpoenas for information. In an extended ... (full story)