So my vague understanding is that QE and stuff is technically printing money, but the resulting money isn't really being used for anything. Is a bubble a bubble if the extra bubbly-ness is from stuff that doesn't get used? EDIT: actually, answered my own question. QE raises asset prices (even if the sellers aren't really doing anything with the money), and at one point people will be like "wait, none of this is worth…
Nobody will just print money and leave it in a vault.