New York (CNN Business) Tesla's stock fell 4% Monday after an analyst said the company will miss its sales target in the fourth quarter. The analyst offered an even more dire forecast: Tesla's shares could be cut in half next year.

Tesla TSLA In October,said that it was "highly confident" sales would top 360,000 in 2019, and in July it gave a range for sales of between 360,000 to 400,000. To hit the low end of that range, Tesla would have to sell 105,000 vehicles in the fourth quarter.

But Cowen auto analyst Jeff Osborne said in a note Monday that Tesla will come in just short of that target. He forecasts deliveries of 101,000 cars in the last three months of 2019. Osborne attributes most of that dour forecast to softer-than-expected sales of Tesla's two luxury models: the Model S and Model X.

Osborne has been fairly bearish about Tesla's stock for some time, giving shares an "underperform" recommendation, which essentially means "sell." His note Monday actually raised both his fourth quarter delivery target from his previous estimate of 95,000 vehicles, and his price target to $210 from $190.

But Tesla's stock is trading at around $420 Monday. That means Osbourne expects the stock to fall 50% in 2020.