Chinese electric vehicle (EV) maker Li Auto (NASDAQ: LI) today reported a 355.8 percent year-on-year increase in January deliveries, but the stock plunged in pre-market trading Tuesday, raising questions about what happened.

Li Auto said it delivered 5,379 units in January, up 355.8 percent year-over-year. Since the Li ONE's launch, cumulative deliveries of the model have reached 38,976 units.

However, it is worth noting that Li ONE delivered 6,126 units in December, which means that January deliveries were down 12 percent compared to the previous month.

(Graphic by cnEVpost)

In contrast, Li Auto's other two Chinese counterparts, Nio and Xpeng Motors, not only delivered far more units in January than in the same month last year but also saw a rise in deliveries from December.

Li Auto delivers 5,379 vehicles in January, up 355.8% year-on-year

Nio delivered 7,225 new vehicles in January, up 352.1% year-over-year and up 3.1% from the 7,007 units delivered in December.

(Graphic by cnEVpost)

Xpeng delivered 6,015 units in January, up 470 percent year-over-year and up 5.5 percent from 5,700 units in December.

(Graphic by cnEVpost)

At one point in Tuesday's premarket trading session, Li Auto was down about 8 percent at one time and is now down 4.18 percent. Nio is up 1 percent and Xpeng is up 3 percent.