It's already too late to buy the stock on sale. From 5 days ago, UAL is down only 0.19%. With DAL -.07%, LUV +4.04%, and ALK -1.54%, it's hard to argue that one-off situations like this event, or Delta's multiple days of cancellations, have much of an effect on investors.
https://www.google.com/finance?chdnp=1&chdd=1&chds=1&chdv=1&...