Refining margins have surged to record levels in recent months, delivering an unusually profitable stretch for companies that turn crude oil into gasoline, diesel and other fuels, even as crude prices themselves have climbed. Analysts attribute the run to a combination of tight refining capacity, strong seasonal demand and supply disruptions.

The question now facing refiners and investors is how durable those margins will prove to be. Historically, extraordinarily high refining profits attract new investment and capacity additions that eventually compress margins back toward historical norms.

Some industry watchers argue structural factors — including years of underinvestment in new refining capacity globally — could keep margins elevated for longer than in past cycles.