Brent crude oil jumped 5 per cent to above $50 a barrel on Friday and had its biggest two-day gain in years, as traders continued to buy back bets against the price. The international oil benchmark rallied by 16 per cent over Thursday and Friday alone. West Texas Intermediate, the US benchmark, gained a similar amount and moved back above $45. The moves capped a volatile week for oil and broader markets. Both oil benchmarks had dropped to six-year lows at the start of the week as China’s “Black Monday” exacerbated fears about a long-running crude glut. “This is a short-covering relief rally after broader markets have stabilised and traders have lowered their expectations for a September rate rise from the US [Federal Reserve],” said Amrita Sen at consultancy Energy Aspects. “Our view is that fundamentally nothing much has changed. The market is still oversupplied. Oil tanker rates have fallen sharply due to lower shipments to Asia.”