Shares of Delta Air Lines Inc. /zigman2/quotes/200327741/composite DAL -0.51% slipped 0.3% in premarket trading Thursday, after the air carrier joined its peers in warning that third-quarter revenue would be hurt by the recent rise in COVID-19 cases. "During the quarter, demand exceeded expectations in July. In early August, the pace of recovery paused due to the sharp rise in COVID cases," Delta stated. The company said it now expects third-quarter revenue to be at the "lower end of prior guidance," when it said in July that revenue was expected to be down 30% to 35% from the same period in 2019. Meanwhile, Delta cut its guidance range for fuel prices to $1.95 to $2.00 per gallon from $2.05 to $2.15 per gallon, raised its outlook for non-fuel unit costs to up approximately 15% from up 11% to 14%, but affirmed its capacity guidance of down 28% to 30%. The stock has lost 1.4% year to date through Wednesday, while the U.S. Global Jets ETF /zigman2/quotes/207744796/composite JETS 0.00% has edged up 0.7% and the S&P 500 /zigman2/quotes/210599714/realtime SPX +0.75% has gained 20.2%.