I'm not sure I would call the a 2nd wave yet.

They also could NOT count our years of AirBNB income as income because they said "There will be another second wave" so they cannot count it as reliable income anymore??

It's much easier to ride the wave

When a second wave of COVID-19 hits, I think they will be skipping the rent again.2.

Rents are fairly strong, but it seems like you'll have to play a bit of speculation game (finding those outperforming submarkets and picking up rentals there to cashflow now, and ride the appreciation wave upwards). 

Agreed, this wave is not caused like the one that happened back in the early 2000's, but none the less, people are out of work and can not make their monthly payments, it doesn't really matter what caused it.   

Will there be a wave of foreclosures next year? 

In fact, this new wave of cases in the states that reopened earliest could sidetrack the fledgling recovery.

It is an old old old game and the wave of training and hype cycles through every few years...among waves of fresh newbies.

When 2020 began, my option trading took a turn and when everything came crashing down I've managed to ride the wave all the way down with a load of put options thanks to my mentor "TheTradingFraternity" on YouTube.