Volatile oil is rocking markets (again)

Why oil's plunge is freaking out the stock market
Why oil's plunge is freaking out the stock market

Volatile crude oil is once again taking the stock market on a ridiculous roller coaster ride.

Don't let the Dow's pedestrian gain of 53 points on Wednesday fool you. The index had been down as many as 267 points as oil prices looked poised to plunge below $30 a barrel. But oil dramatically rebounded to close above $32 -- carrying the stock market along with it.

The oil market seemed to benefit from a new report showing stockpiles of gasoline and heating fuel fell more than expected last week. Of course, that same report revealed another surge in oil inventories to a new record high.

Overall, the oil markets remain rattled by the latest chaos within OPEC. On Tuesday Saudi Arabia ruled out the idea of cutting production, while Iran blasted the Saudi-led idea of production freeze as a "joke." What a mess.

Related: Why people are freaking out over cheap oil

IMF head Christine Lagarde told CNNMoney she's worried sluggish global demand means oil prices are "going to be low -- and for longer."

"Those countries that were massive consumers of oil are reducing their consumption," Lagarde said. "China, for one, has not reduced so far but will probably reduce in due course."

All of this is very important to the stock market, which has become obsessed with the downsides of cheap oil. So far in 2016, oil and the S&P 500 have moved together 87% of the time, a CNNMoney analysis found.

Just look at last week. The Dow soared 418 points -- its best performance of 2016 -- after oil prices climbed back above $33.50 a barrel.

--CNNMoney's Heather Long contributed to this report

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