I think that relative mismatch would imply Short F9, Long NK - but us puny retail guys cannot short new IPOs, and I am not gonna put more eggs in the NK basket since I already into them for over 7 digits (future earnings)

SO - I am gonna do nothing.
Other could be inclined to buy SAVE instead of ULCC.
If F9 valuation holds, NK could take a nice 50% jump from 37 to 57! YAY....
If NK valuation holds, F9 could drop 1/3 from 19 to 12 - I hope not

I think the LCC & ULCC will do better over the next few years. and both will do better - Just NK has more headroom...