What's going on?

Delta Air Lines shareholders were dealt a pleasant surprise when they checked into the market on Tuesday: the carrier�s stock price got a 4% upgrade after quarterly earnings beat expectations.

What does this mean?

Delta�s financial results for late 2019 overshot the runway: revenue was up 6.5% on a year before, while profit flew more than 30% higher. That was partly down to cheaper fuel lowering costs and domestic demand from US flyers hitting an all-time high over the holiday season. But Delta also banked on the sale of its stake in Brazilian airline Gol, recently ditched in favor of an�investment in larger competitor Latam.

Delta cemented its status as a high-flyer, too. Revenue from its premium cabins � business and first class � grew 9%, twice as fast as economy-class revenue. There may be some mild turbulence ahead, however: the airline said flying costs could rise by up to 3% this quarter, partly due to higher staff salaries.

Why should I care?

For markets: Boeing, Boeing, gone.
Another contributor to Delta�s quality quarter was the Boeing 737 Max debacle. While Delta doesn�t fly the grounded plane, its competitors do � so when they canceled flights, travelers turned to Delta instead. If and when Boeing�s jets get set to fly again, Delta could lose out. But its loss may be America�s gain: the US treasury secretary warned on Sunday that Boeing�s woes could reduce US economic growth this year by 0.5 percentage points.

Zooming out: Vertigo or acrophobia?
Air travel is a mercurial industry, and success often lies outside companies� hands � as the recent mixed fortunes of two European airlines lay bare. Low-cost Irish carrier Ryanair raised its earnings forecast last week, saying bumper Christmas bookings could boost profit by $165 million. UK regional carrier Flybe, however, is flying on empty: a weak pound and Brexit uncertainty have hurt its bookings, forcing it to look to the UK government for a parachute.