Despite a 20% slump in oil prices in 2025, the world’s biggest international oil firms saw their stocks rise by 4% to 18%, breaking the correlation between crude prices and oil stocks. Last year, investors appreciated the returns that were kept despite the oil price slide. They also cheered the strategic pivot of European majors to focus back on boosting their upstream production, Exxon and Chevron’s record-breaking Permian output, the synergies the U.S. supermajors began reporting from recent multi-billion-dollar acquisitions, and…