Ultimately the bitcoins are a digital file that we ascribe value even though there's no inherent entity, and we trust in its value because someone assured us that a computer is sure it's a unique file. So what's a weird thought to me is, when did these accounts actually go to being valueless?
It's like... Pretend there was no insurance or regulation, and I had a bank account with no physical cash, but just a computer entry saying I had $5,000, and the bank has $5,000 to cover it if I need to withdraw. The bank lends out that money, invests it, whatever, and now does not have the $5,000 on-hand to cover my account. Then at some point, the banks investments go belly-up and people stop paying off their loans, and the bank is unable to get enough money together to cover my $5,000, but they still have the computer entry saying I have $5,000. Finally, I go to withdraw it, and they tell me they can't give me my money, and they go out of business.
So the weird question is, at what point did I actually go from having $5,000 to not-having $5,000?