actually an explosive growth in price is one of the main signs of a bubble in existence. but the thing is that bubbles burst and the market corrects itself. it doesn't mean ALL the rise should go away just because it was explosive. for example if we have $100 rise that leads to a bubble the correction is $20 of that going away not the whole $100 rise. and that is the part that people confuse. they think the whole $100 should go away and price should go back to the initial value for the bubble to stop existing.
although you should not confuse a "bubble" in a real asset like bitcoin with a "bubble" in a pump and dump altcoins. the later is completely fake price so it needs to go back down to initial value. in other words it needs to lose the whole $100 rise to exit the bubble.