Brent crude futures fell $1.91 to settle at $87.07 a barrel on August 13, while U.S. West Texas Intermediate dropped $2.02 to $81.25, reversing a roughly week-long rally as investors weighed slowing global demand against renewed supply risks. Brent snapped a six-session winning streak and WTI ended a five-session run of gains, with both benchmarks down more than 3.5% earlier in the session before trimming losses. Pressure came from concerns that weaker economic signals in China and Europe could curb energy demand, while weekly U.S. Energy Information Administration data showed commercial crude inventories excluding the Strategic Petroleum Reserve rose by 17.4 million barrels in the week ended August 7 to 424.4 million barrels, the largest weekly build since January 2023. Losses narrowed after reports that Yemen's Iran-aligned Houthi militant group attacked a Saudi Aramco-operated refinery with drones, reviving concerns over supply disruptions and crude transport risks around the Red Sea.