Tesla shares edged higher in early Friday trading, but have lost nearly have of their value since mid-December, and a top Wall Street analyst suggests there could be more declines ahead tied to weakness in the group's core automaking business.

Tesla backlash continues as the stock nosedives and Musk pushes conspiracy theories about protests and arsons at dealerships.

The first place I would look for a clue from Tesla options is the weighted put-call ratio. That chart is shown below. There was a local minimum at an extremely low level last Dece