It's a crude reality for the market: Oil will put an end to the rally. At least, that's what some market participants contend.
"The increase in the WTI oil price is creating too strong a headwind for growth and further equity gains," Encima Global President David Malpass wrote on Wednesday. "We think there will be a pause or retracement in equities until growth prospects improve or oil falls."
Over the course of three weeks, oil has rallied 12 percent to the highest level since March 2012, and Malpass believes that rising oil prices could pose a problem both for consumers and for businesses.
"It's an important cost of doing business, and may undercut profits and business confidence. From the standpoint of the consumer, it acts as a tax increase, reducing the income that could be spent elsewhere," he said.
One of the reasons Malpass is so concerned about the oil rally is the reason behind it.
"Expensive oil brings new negatives," Malpass said, and "this is particularly true when the increase in oil prices is caused more by supply concerns than an increase in demand."
(Read more: Here's when high oil prices could really pinch)