If you call going from $1000 to $19,000 in a year then declining sharply a bubble, then sure, it's a bubble.

But if you factor in that it didn't go crashing back down to zero but hit resistance points at $10,000, $9,000 and $8,000 and is now testing $7,000, then it's deflating slowly rather than bursting.

But even if it slides all the way down to $2,000, it still almost doubled in a little over a year. I'll take that kind of bubble every day.