Updated from 2:10 p.m. EST

The bottom may have fallen out of the oil market -- finally.

Crude oil prices fell sharply again Thursday after a 7.4% plunge Wednesday, the biggest one-day loss in three years.

Based on preliminary data, the January futures contract lost $2.24 to $43.25 a barrel in Nymex floor trading, a level not seen since September. Just Tuesday, prices briefly touched $50.

Wednesday's dramatic selloff came after weekly inventory data showed a surprisingly large increase in U.S. energy stocks during the most recent week. In particular, a jump in heating oil inventories eliminated recent concerns about supply ahead of the winter season. In addition, a National Weather Service forecast for warmer-than-normal temperatures in the week ahead also pressured prices.

The benchmark U.S. crude is now down more than 20% from its closing record high of $55.17 in late October, when U.S. production was still hurting from the widespread disruption of Gulf of Mexico facilities caused by Hurricane Ivan. Prices suffered a previous correction in July, but recovered in August and hit new highs.

Nevertheless, prices are still up sharply on the year amid unusually strong global demand, which has stoked enormous market speculation.