What's your odds that we will face much more strong correction for the whole market in a very near future?
99% of these terms such as bubble are a shaky definition at best. if you read more about each of them you can see there is always a lot of ifs and buts and never a clear things saying "if this then it is bubble." by definition a bubble is when the price strongly exceeds the asset's intrinsic value. but the problem is defining the "intrinsic value" now.
what is this value, for bitcoin is it $10, is it $2000 or is it $10,000?
for altcoins the same.
but the thing to remember is to look from where the price or that value comes from. sometimes it is coming from real utilities such as merchant adoption of bitcoin, and sometimes it comes from pure speculation like most altcoins and most of the time it is simply pump. in the last case it is obviously a bubble and it will drop and these drops are fast and clear.
in the second case since the bubble in not a clear thing, it will take time to burst and because people don't believe it, they still buy in and slow it down. but it is inevitable. and this usually can be seen on the charts with an over all dip with dead cat bounces.
the first case is usually a big rise followed by a big drop (correction) and then stable price with no further drops. this is what i see on bitcoin charts for now.
unexpected events such as a chain split or any other incidents such as exchanges getting hacked, running away, ... or simple FUD does not count towards the dips.