All three major U.S. stock indexes ended the session sharply lower, with the S&P and the Nasdaq suffering their largest one-day percentage drop since mid-May.
Under the agreement, the airline will purchase 15 of Boom's "Overture" aircraft once they meet United's safety, operating and sustainability requirements, with an option for an additional 35 aircraft.
United said the aircraft would be optimized to use 100% sustainable aviation fuel (SAF) from its entry to service, projected to be in 2029.
Yields on longer-dated U.S. Treasuries fell for a fourth straight day, with the benchmark 10-year yield hitting a fresh two-week low of 1.564pc and helping to ease inflation worries.
The company said it now expects first-quarter revenue to fall 66% to $3.2 billion from the same period in 2019. It had previously forecast a drop of between 65% and 70%.
The airline said its average daily cash burn for the quarter is expected to be about $9 million per day, an improvement of about $10 million compared to the fourth quarter of 2020.
