GM, Ford 'safer bets' than Tesla -investor

Tesla has the lead in the electric market but General Motors and Ford are pouring billions into the technology to upgrade proven best-sellers like the Ford F-150 truck and GM's Cadillac Escalade with plug-in versions, says Kramer.

She fears Tesla's stock is headed for a crash back to earth.

Kramer made her remarks after Hertz announced Monday that it would buy 100,000 electric vehicles from Tesla, sending Tesla shares to a record high.

GM and Ford are scheduled to release third-quarter results on Wednesday.