The airline sector experienced a significant downturn as oil prices climbed, with Brent crude exceeding $90 a barrel. This surge is primarily attributed to escalating geopolitical tensions, including a U.S. strike on Iranian launchers and subsequent retaliation. Rising jet fuel costs are a major concern for airline profitability, as fuel is a primary operating expense. Adding to the negative sentiment were weak first-half earnings from major Chinese airlines, which also cited the impact of higher fuel costs.