U.S. commercial crude oil inventories have declined for five consecutive weeks, while diesel inventories have fallen below 100 million barrels, reaching their lowest level since 2003.

U.S. commercial crude oil inventories have fallen for the fifth consecutive week, with a drop in distillate inventories far exceeding expectations, further heightening market concerns about tight supply.

Data released Wednesday by the U.S. Energy Information Administration (EIA) showed that for the week ending October 30, U.S. commercial crude oil inventories (excluding strategic petroleum reserves) decreased by 865,000 barrels to 409.8 million barrels, about 4% lower than the five-year seasonal average. The market had previously expected a decrease of about 200,000 barrels.

Distillate inventories plunged to the lowest level since May 2003, 13% below the five-year average, prompting caution in the market.

Meanwhile, inventories at the Cushing, Oklahoma delivery hub rose slightly by 280,000 barrels to 27.3 million barrels, while Strategic Petroleum Reserve (SPR) levels decreased by 399,000 barrels to 282.2 million barrels.

As of press time, WTI crude futures were down 8.8% on Wednesday.

The most notable data this week was the sharp decline in distillate inventories.

Distillate fuel oil (including diesel and heating oil) inventories fell by 3.6 million barrels to 99.3 million barrels, not only 13% below the five-year average but also the lowest since May 2003. The market previously expected a decrease of only about 1 million barrels—the actual decline far exceeded forecasts.

With the Northern Hemisphere heating season approaching, persistently low distillate inventories will place additional pressure on related supplies.

Gasoline inventories fell by 22,200 barrels to 209 million barrels last week, about 2% below the five-year average, while the market had expected an increase of 200,000 barrels. At the same time, gasoline demand recovered, rising by 450,000 barrels per day to 8.8 million barrels per day.

Last week, refinery operations accelerated notably. Crude oil throughput at refineries increased by 199,000 barrels per day to 16.7 million barrels per day, and refinery capacity utilization rose from 92.8% the prior week to 94.5%, above The Wall Street Journal survey’s forecast of 92.9%.

In terms of imports and exports, U.S. crude oil imports remained at 6.4 million barrels per day, while exports decreased by 1.2 million barrels per day to 3.7 million barrels per day, resulting in a net import increase of approximately 1.18 million barrels per day.