Delta Air Lines vs United Airlines: a pairs trade breakdown

The relative-value spread between Delta Air Lines (DAL) and United Airlines (UAL) highlights a fascinating dynamic in the aviation sector. As of September 15th, DAL trades at $78.93, down 1.09% from the previous close, while UAL is priced at $106.10, slipping 2.62%. The pair trade exploits the price difference between these two closely correlated airlines, rather than betting on their individual performance.

These airlines share numerous macroeconomic exposures, including fuel costs, capacity, and demand. When one airline outperforms the other, a mean reversion typically occurs, making the pairs trade a popular strategy. Since June 30, DAL has outperformed UAL by 34 percentage points over the past year. Analysts maintain positive ratings for DAL due to its stronger balance sheet and ongoing debt reduction, despite recent price declines.

UAL's higher leverage, driven by inflated fuel cost estimates, amplifies its downside risk in a stress scenario.

Despite UAL's cheaper traditional multiples, DAL's intrinsic value model suggests a 11.3% upside, while UAL is 3.6% above its fair value. Therefore, DAL commands a structural valuation premium. Should fuel costs normalize and the spread compress back to historical parity, a long UAL / short DAL mean-reversion trade becomes more attractive. However, DAL currently offers better risk-adjusted value due to its lower leverage and positive fair value outlook.