There are two different aspects:
* lack of liquidity during a crisis (no one willing to catch the knife)
* lack of market access.
I think both aren't much affected by the lack of transaction speed on the blockchain? E.g. suppose you want to quickly sell your bitcoin, ..
..1 ) but there is no-one there to buy it? That has nothing to do with exchanges or transaction speed. It's because potential buyers are having lunch, playing the tetris, aren't really interested no more in buying a bitcoin.
I'd think that the relative amount of interest in eating lunch versus buying bitcoins would be a strong function of how easily one can use bitcoins or sell bitcoins. That, in turn, depends on the frictions in the transaction system. Would you put your money in a bank that had ATM fees of €5 on some days but maybe €20 other days or that maybe you have to wait a hour for your money or maybe you have to wait 3 days to find out that your transaction never went through? Transaction friction directly affects liquidity and liquidity (relative to holding times) directly affects price.
.. 2) You want to dump it at $45.000, just 5% of the value of the previous day,.. someone else really want's to buy it for $45.000 here at the W forum, .. and so you agree to exchange the money and promise to move the bitcoin to his wallet when there is a transaction slot in the blockchain. You can write a simple contract.
I don't think thats how it works, transaction slots don't come up to you like a taxi and then you put in whatever order you want. Instead, you submit your specific pre-defined irrevocable order with a pre-defined counterparty into an irrevocable queue.
that sound like a solid defined moment & fact of transfer of ownership of the coin leg of a trade agreement.
If the price of bitcoin falls while the order is pending, there's nothing the buyer can do except breach their side of the contract (or hope the blockchain order never gets confirmed).
The price of bitcoin doesn't exist as a global property, and coins can be transfered like any other type of transactions people do.
1. you can trade bitcoins without a price, I can donate bitcoint, no need to exchange them for dollars.
2. there are various exchanges where you can swap bitcoins for other currencies, different exchanges have different prices -not because there is no high freq arbitrage trading going on- but because each exchange has it's own credit risk: they can get looted and go bankrupt. That credit risk ends up in the price because before you can trade you will have to transfer funds to that exchange. This is very much like banks.
3. when you trade at an exchange there is no "price", when you want to sell you can look at bids and different exchanges will have different bids. This is very much the ame as you see with ECN exchanges.
4. you can trade with a paper contract and an invoice! You pay the invoice and 2 days later the money you've send to my bank account will arrive.
But lets say you are still willing to dump bitcoin for 5% of the previous day's price. Why wouldn't the potential buyer think that they can wait an hour and get the order for 4% of the previous day's price?
When you trade with someone and agree on a price, you agree to some sort of contract that seals the deal. You either trade at 5% or not, .. you don't have an option to wait for another hour and change the price of your trade. E.g. if I would send you an invoice for 10 Euro based on some service I delivered as promissed then that's what you owe me. If you wanted to hedge that you have had to do it the minute you agreed to the deal were I would do a service and you would pay for it, that's the timestamp of our trade. The fact that you will pay later, and that the banks will hold the transaction in a twilightzone for two days doesn't change out agreement.
And to the extent that your order is public (which it needs to be if you actually want to find a decent buyer), then why don't all the other would be buyers of bitcoin revise their bids to 4.99% of the previous day's price?
But worse: if the buyer thinks the price is falling 16% per hour (i.e., a 95% drop in price per 14 hours) and they know that bitcoin's slow transaction system commits them to owning those bitcoins for at least 1 hour and possibly as long as several days, then why wouldn't all buyers wait on the sidelines for the price to stabilize?
You don't need settlement in the bitcoin blockchain to agree on a price or exchange ownership of coins vs dollars, and an agreement to exchange bitcoins for dollars is binding, you can't just pull out. Once you agree to a a trade at an exchange, the exchange will make sure that payment are done and coins exchanged. Fund and coins will imediately be transfered (un)locking the ability to immdiately trade once more at the exchange. The exchange keeps track of ownership, and that will materialize in the blockchain when you take the coins out of your exchange account.
However, nothing is stopping you to get drunk with a friend X and write on a matchbox "we agreed that t4a wil buy from X 1`bitcoin for $19.000, friend X will transfer is within a week, t4a will move the money to an escrow account, bla bla bla more legal clauses". Now suppose you wake up the next day and the price of the bitcoin is $30.000. Your friend "can't rember this agreement you two make last night". Now what?