Graph of gasoline prices

From an article in the Wisconsin State Journal, which raises the question as to whether this is a temporary "bubble" caused by world geopolitics and seasonal and refining changes, or whether it is the forerunner of a longer-term trend.

Interesting addendum (posted later the same day).  Headline from HuffPo:

Oil Prices Plunge In Record Sell-Off

NEW YORK -- Oil prices took a nosedive Thursday in a historic selloff, erasing weeks of gains and indicating that the months-long climb in energy prices may have hit a ceiling.

Crude oil plunged 10 percent as startled investors unloaded their positions and a weeklong decline accelerated into an outright freefall...

"There was no triggering single event of news that would account for this. It's just much more the market's own internal dynamics taking prices down here," Richards added.

"The market's own internal dynamics" -  that doesn't translate to simple supply and demand...

Second addendum:  Best article I've found on the selloff is the one in the Wall Street Journal.