Markets were mixed on Monday.
The S&P 500 rose 0.8 percent but the STOXX Europe 600 slipped 0.1 percent and the Nikkei 225 plunged 3.1 percent.
US crude oil fell 2.5 percent as a Bloomberg report suggested that the oil price rally is not as deep-rooted as it looks at first glance.
The report noted that while front-month futures for US crude have risen 21 percent this year, the five-year-forward contract fell 2.6 percent over the same period. It suggested that this reflects the view that shale oil production could rebound as prices recover, capping any rally.
This in turn means that oil stocks may have rebounded too far, with some analysts saying that energy stocks are already pricing in significantly higher long-term oil prices.