I don't know if this could be the "bursting of the bubble" they're talking about. But I think this just just a normal thing with bitcoin. Especially Christmas is coming and a lot of people trying exchange bitcoin to fiat so they could use it.
This is really what they call "bursting of the bubble", it should happen a few days ago which is more relevant to happen but it burst just right before christmas, im not surprise that it happen im more surprise by the price increase from $9k to a woopping $20k in a couple of days.