The first nine months of the year were excellent, marked by a return to normal traffic volumes, market share gains and record capacity. United should generate between $2 and $2.5 billion in free cash flow by 2023.

That's tempting if you look at the market capitalization of $13 billion, but much less so if you look at the enterprise value - which includes net debt - of almost $35 billion. In fact, the normalization of traffic was already factored into the valuation.

The airline sector remains largely uninvestable. In addition to a structural inability to create value - the fault of a hyper-capital-intensive, hyper-unionized, hyper-competitive and hyper-cyclical business - they regularly go bankrupt.

The American sector has consolidated between the four major companies, but remains at the mercy of the first unforeseen event. The painful experience of the pandemic proved the point. In United's case, the episode neutralized all the effects of the share buyback strategy implemented by the company after the great financial crisis of 2008-2009.

The idea looked good on paper. In practice, as usual, the result was a major destruction of value, with the share price returning to exactly where it was ten years ago.