That’s because the correlation between crude oil and stocks has not been stable over time. For several decades prior to 2000, for example, that correlation was negative, as you can see in the chart below. During those decades, higher oil prices in a given month led to below-average stock-market returns in the subsequent month.

A disruption to global oil flows could send prices higher. That would be good news for Russia, with oil being a key lifeline to sustain its war in Ukraine.