The United States Oil Fund (USO) tracks the daily price movements of West Texas Intermediate light, sweet crude oil, and is therefore directly impacted by changes in oil prices. The geopolitical event involving the death of a Hamas leader, which could lead to regional instability, initially caused oil prices to rise. However, the subsequent decline in oil prices, likely due to market reassessment of the situation or other factors not mentioned in the article, led to a decrease in USO's value. The short-term impact is negative due to the immediate market reaction, but the situation remains fluid and further developments could affect USO's performance.