What happened
Tesla (TSLA 2.44%) shares dropped another 5% Thursday morning as more news from the fourth quarter came out. Tesla stock has now dropped more than 70% over the last 12 months and is at its lowest level since August 2020. As of 11:05 a.m. ET, shares were hovering near the morning lows, down 4.9%.
So what
It seems like one item after another pops up to explain why Tesla shares continue to slide. The stock dropped almost 40% in December alone. More recently, investors were unhappy with its fourth-quarter and full-year 2022 vehicle delivery report. Today's decline is related to that, with one critical new data point from that information.
Now what
Earlier this week, Tesla reported a shortfall in fourth-quarter deliveries, with just over 405,000 electric vehicles sent to customers in the quarterly period. That disappointed investors, who now know vehicles coming from its Shanghai, China, plant were a key reason.

Image source: Tesla.
Data provided by China's Passenger Car Association showed Tesla delivered fewer than 56,000 vehicles from the Shanghai facility in December, reports Barron's. That was a sharp drop from its most productive month ever, November, when it delivered or exported more than 100,000 units from the Shanghai facility.
The drop is particularly concerning since that plant is thought to be the most profitable for the company. It was also the focus of recent investments that increased its annual production capacity to about 1.1 million vehicles. The December drop from that plant has investors wondering where profit margins will come in. That important data will be released on Jan. 25, when Tesla reports its fourth-quarter and full-year financial results.