Seems to me that it won't be the brick hitting the water that'll drown us, it'll be the ripple-out effect.
If the global maximum of 21 million bitcoins had been mined and issued, and if each one was worth $20,000, and if they all lost 99% of their value next month, then the world's stock of bitcoin value would have dropped from $420 billion to $4.2 billion. And $415.8 billion would be enough to keep Donald Trump in cheeseburgers for about a week.
Not much more. (Mild overstatement, there. $415 billion is about a week's GDP for the United States.)
Troubles will happen because some institutions will have over-exposed themselves and will face liquidity issues, which will have knock-on counterparty effects all over the place. Bitcoin in itself won't be the cause of a financial avalanche, but it might be the trigger for one if the preconditions are already in place elsewhere.
Bear in mind, though, that all the above figures are fake news. On the one hand, not all bitcoins have in fact been mined, and anyway there are dozens if not hundreds of other cryptocurrencies out there. Coinmarketcap said this week that the total global value of cryptos was $760 billion (
https://www.prnewswire.com/news-release ... 30353.html).
Tell you one thing, though. If bitcoin crashes, there are going to be a hell of a lot of very disgruntled young people who've convinced themselves that bitcoin is the only kind of lottery ticket with a guaranteed 100 thousand percent payout. I expect they'll find a way somehow to blame it all on the baby boomers.
BJ