This actually a price increase because of a loss of the federal tax credit... the title is bogus and should be changed imho. "Moving beyond the success of Q4, we are taking steps to partially absorb the reduction of the federal EV tax credit (which, as of January 1st, dropped from $7,500 to $3,750). Starting today, we are reducing the price of Model S, Model X and Model 3 vehicles in the U.S. by $2,000." http://ir.te…
The ceiling in the title refers to a ceiling of what customers are willing to pay. Tesla apparently believes customers won't pay the full price without incentives, so they're cutting the price they charge you.
While it's an increase in the sense that the government stopped making it cheaper for you to buy a Tesla, it's still a decrease for Tesla as a company, and that's what has investors nervous. (Rightfully or not is another story.)