America’s two biggest oil companies posted bumper Q3 profits on surging refining margins, rewarding shareholders while tech earnings disappointed.

Big Oil had a blockbuster quarter. ExxonMobil earned $15.4 billion in Q3 — $17.5 billion adjusted — beating forecasts on record refining performance and revenue of $110.5 billion.It returned $9.4 billion to shareholders and lifted its dividend.

Chevron’s profit nearly tripled from a year earlier to $9.9 billion, helped by record refinery throughput and US production above 2 million barrels of oil equivalent a day.

The common driver is refining: with fuel supplies tight, margins on diesel and other products have widened far more than crude prices.

The results stood in sharp contrast to the week’s tech earnings rout.