https://www.forbes.com/sites/willhor.../#27e60e587cdf
Flybe sold 25 Gatwick slot pairs to EasyJet for £20 million in 2013 while EasyJet last November spent £36 million on former Thomas Cook slots for 12 pairs in summer, eight in winter plus additional slots at less congested Bristol. Norwegian last September securitized a loan with $380 million worth of Gatwick slots.
The real values of the slots have fallen dramatically in 2020, no NAS flights, no BA, no Virgin, perhaps even a reduction in TUI flights we could be looking at something like 35% of the slots becoming available this summer (what's left of it!) and a fire sale. GAL can reduce their overheads simply by closing one terminal but the airlines are still left with fixed costs for parking, maintenance and movements.
If you are an airline depending on the collateral value of these you will be in trouble. BA don't care they just want to protect their LHR position and Virgin will re-group there if they continue. If Wizz move into LGW they will be a tick in the side of Easy, but EJ does not have the cash to pick up the extra free slots at this time.