(Reuters) -Elon Musk and Tesla were sued by shareholders who accused them of securities fraud for concealing the significant risk that the company's self-driving vehicles, including the Robotaxi, were dangerous. The proposed class action was filed on Monday night, following Tesla's first public test of its robotaxis in late June in the company's Austin, Texas, hometown. Tesla's share price fell 6.1% over two trading days after the test began, wiping out about $68 billion of market value.