For much of this year stocks and oil have traded in tandem, with both falling.
But, "this is not normal," Michael Block, chief strategist of Rhino Trading, tells
CNNMoney. "This is not fundamentals."
For the past few years, stocks and oil haven't moved together often. In fact, the correlation between stocks and oil prices totaled only 20 percent. But since the beginning of 2015 the correlation has soared to 60 percent or more, reaching 90 percent for some three-day periods, he explains.
So why the increase? The drop in oil prices to 5 ½-year lows has panicked investors, leading them to sell other assets without too much thought.
"It's the pain trade," Block notes. "Stock prices aren't just driven by fundamentals. They're driven by who owns what."
But perhaps the link is breaking. Stocks have risen recently while oil prices have fallen.
Clarity might come as companies reveal the effects of lower oil prices in their fourth-quarter earnings reports, Dan Greenhaus, chief global strategist at BTIG, tells CNNMoney.
"As you progress through earnings season and see more energy and industrial companies, you start to see a more concrete understanding of what the effects of lower gas are. Right now it's a guessing game," Greenhaus contends.
Meanwhile, financial writer/money manager Willem Middelkoop says the oil price drop stems partly from U.S. "economic warfare" against its enemies.
"The current price can only partially be explained by technical factors like growing U.S. oil production," he tells Russia's state-controlled
RT news service.
"The price declines were also caused by heavy selling in the American futures markets, and you could call that a form of economic warfare."
And what warfare is that?
"It is an all-out economic war between the U.S. and Russia now," Middelkoop explains. "If we see who has more problems [caused] by current oil, they are Russia, Iran, Venezuela. These countries can be seen as enemies of the U.S."