It's a very curious bankruptcy.
By its own admission UAL will be cash flow negative to the tune of $15 million a day this month. Under the terms of their DIP financing, they have to become cash flow positive by the end of February.
So I'm not sure how slashing business fares will help. They'll get some more passengers, but at what cost?
Nor am I sure how much it will hurt Frontier, BA. Those high end pax aren't targeted by F9. Yes, they may lose some, but hey, on F9 you still get some food, and, on certain flights, PTV. Although the official start up of the PTV's won't be announced until more aircraft are retrofitted, apparently they've been offering it for a while as a freebie, and on 1 January began charging the $5.
Roundabouts and swings.