You can know that bitcoin is doomed to fail, but that doesn't help you if there's a temporary price spike and you get a margin call.
(this will have occurred in the scenario where a few (or few hundred) bidders matter)
But the bubble has supposedly popped many times, keep in mind Bitcoin has had crashes far greater than just 50% before (closer to 90% has happened multiple times, see https://en.wikipedia.org/wiki/History_of_bitcoin#Prices_and_...). So if this is 'the' bubble pop, rather than just another large crash, will remain an open question for quite some time.
What seems apparent to me is that all the Bitcoin miners that have invested heavily in mining equipment want to see it continue to grow. The market may only slow down once miners no longer see a return on further investment (when the increasing price of electricity + mining equipment, combined with the steady rise of hashing difficulty, no longer makes it profitable), or when the transaction fees and transaction speed become too much of an issue. In other words, it's the technical limitations that seem most likely to stop the rise of Bitcoin (in my opinion).
How much money would World of Warcraft gold be worth when that game eventually shuts down?
How much money will any amount of Bitcoin be worth when the Bitcoin network frays apart and ceases to function?
It's true that is the price goes low enough mining would decrease significantly, but after difficulty adjustment it would still exist to a nonzero extent. Bitcoin can absolutely still function as a system even if 95% or even 99% of all miners end up quitting it over the next few years.
Bitcoin isn't. It's merely distributed and it depends on having a singular, healthy, functioning consensus network. Where that network splits you suddenly have more than one blockchain, as is the case with Bitcoin Gold, and Bitcoin Cash.
It also depends on having a healthy balance of mining power in that network so that no one entity can take control and start to dictate terms.
If all that's left is a single miner then four other miners can easily take charge of that network and effectively destroy it.
> Bitcoin can absolutely still function....
The blockchain component of Bitcoin can technically function, sure, there's no problem there, but as a unit of value, as a unit of exchange, it's functionally useless. You can't trust it, you can't use it for anything.
There is, by design, one blockchain. When that assumption fails, the network has to work to achieve consensus, and if that can't be achieved it splits. That can be fine with things like IRC networks or peer-to-peer exchanges, you can always do a messy reconciliation later, but with something that's supposed to represent a medium of exchange that's a problem.
Non-negligible value of BTC also depends on constant investment of electricity in mining more Bitcoins and companies dedicating resources to maintaining payment/exchange infrastructure
It's really hard to take someone seriously when they say the price is going to literally go to zero. It's possible to imagine crashes of 90% or even much worse for an asset like Bitcoin, but a market price of zero would suggest not a single person in the world is willing to pay anything at all for a Bitcoin. Absent a world-changing event like hashing being completely broken, the price will never be exactly zero. I can guarantee this since I myself would be willing to pay at least 1 cent for every BTC that exists, and I know that many would be eager to outbid me with that offer.
If someone is so good at calling the exact extent of this crash, then they should place a short on Bitcoin. You don't have an excuse anymore. It's on regulated markets, unrelated markets, and everything in between. If you really think it's going to zero then put all of your money in a short and make sure not to close it until it gets there. Options are also available for some investors, which should be even more lucrative for you.