If it took 10 years for it to fall 30% in one month, it would depend on all the activity in between, and where the value ended up relative to the original point

If it took 10 years for it to fall 30% in one month, it would depend on all the activity in between, and where the value ended up relative to the original point at which a bubble was called, in real (inflation adjusted, not nominal) dollars. If there was a complete economic cycle or two during that time, then the original call for a bubble would have been mistaken. However, if it were still the same economic cycle, then that bubble would have been called correctly, regardless if it was 5 years, 10 years, or any length of time. And I was not defining a bubble, I was simply noting that a bubble and a market top are not the same thing. At any point where prices trend significantly upward, beyond historical cyclical patterns, there is a potential for a bubble. Whether that trend is indicative of a permanent market shift or whether it is a temporary phenomena where prices will revert to the mean afterwards is what decides whether or not there was a bubble. Whether you are at the start of a bubble or near the end of a bubble doesn't change whether or not it's a bubble.