After Tuesday's losses in the U.S. crude oil market, bullish sentiment was bolstered by a key industry report about the supply of Texas Tea. Overnight trade in WTI crude was buoyed by the American Petroleum Institute's estimates that indicated crude inventories falling much more than analysts' expectations.

Crude oil futures tumbled in early trading today after government data showed surprising buildup in oil inventories.

Last week's Desktop piece, "Oil Fundamentals," illustrated the connection between contango in the West Texas Intermediate crude market and U.S. oil inventories. Contango, in case you missed the article, refers to successively higher premia built into the prices of futures reflecting the costs of carrying the commodity until delivery.

Sometimes readers wonder why so much attention is paid to the weekly oil inventory numbers published by the U.S. Energy Department's statistical service. Truth be told, a lot of trader breath is held awaiting each Wednesday morning release by the Energy Information Administration.

Whether you see BP's current performance as a potential buying opportunity or a sign of bleaker times to come, it pays to know how much influence its presence is having in your ETFs.

Oil gained modest ground in the overnight market in anticipation of this morning's holiday-delayed inventory report from the U.S. Energy Department. Prices for West Texas Intermediate crude futures rose 0.4 percent on Wednesday's NYMEX floor session.

Amid all the hoopla and volatility of the past few days, you might not have noticed the compression in refining margins. Normally, refiners' profits fatten through mid-May as gasoline for the summer driving season is contracted.

Just how sensitive are the oil majors to crude prices? The answer might surprise you.

Crude oil prices were lower overnight, but recovered in a run-up to the Wednesday opening bell and the U.S. Energy Department's weekly inventory report. The NYMEX June contract, set to expire at the close Thursday, has slumped $7.39 a barrel in six successively lower closes, pressured by concerns about Europe's debt problems and a buildup in U.S. crude inventories.

Overnight trading in U.S. crude oil was volatile and generally weaker following Tuesday's NYMEX session that featured front-month prices settling a half-percent lower.