I've only been in BBUS for around 12 months, so can't advise of...

I've only been in BBUS for around 12 months, so can't advise of the liquidity from yeas ago.
But I'm assuming there must have been a very high degree of fear at the time, plus a sustained period of heavy equities selling.
You'll note that punters filled their boots on equities again today, so when we get three or four waves of selling they will either take big losses or buy BBUS to cover. There is still plenty of money around, so we're no where near the bottom of the market.