Not vapour money for me ...
Less than 2 years ago on a whim I bought £1000 of BTC. Last Xmas I cashed half of those BTC for £4000 and had a pretty good holiday with it, with a lot left over. The other half of my BTC that remains is now worth less than £2000, but even if it was worth nothing, I reckon a 400% return in just over a year is pretty good, and it certainly did not prove to be a stupid investment (which many people told me at the time). Meanwhile the savings in my current account have earned zero and in fact lost value due to inflation.
ISTM that the bubble is not so much in danger of bursting, but is more at risk of being deliberately popped.