It is only a matter of time...
Estimating the exact time when a bubble is due to collapse can be a difficult exercise and extremely hazardous to one's financial health, because, as John Maynard Keynes put it, "the markets can stay irrational longer than you can stay solvent."
Note that it only takes a relatively minor event to prick a bubble, but once it is pricked, the bubble cannot "inflate" again.