You mean flash crash and then immediately back to +$200? Or you are saying that those who sold at 160btc will be queing up to buy like crazy at $123.40 (Gox last price)?
Why would anyone queue to buy at $123.40 when they can buy at $88 right now on another exchange?
No they CANNOT. Explain to me how I can buy 10,000 USD of bitcoin RIGHT NOW on any other exchange? You would have to have an account open with them AND have USD sitting in that account.
If you know me, you can. You will have to send me 100% of the amount in BTC as a guarantee. I can buy in any exchange as I have money in all of them. For a fee, of course. The ones doing this will make a killing tomorrow as they did today, irrespective of what happens to the price.
I don't believe it will go sub-$20. I am not the only arbitrageur out there. Everybody wants bitcoins. If you don't believe me, sell yours to me.
You have the trade I say cannot be done backwards. I am saying for people that believe in bitcoin and have CASH (fiat), you CANNOT get that cash into one of these exchanges in quantity to BUY bitcoin. But, you CAN move BTC quickly and SELL it. That makes the selling pressure high. Great buying opportunity that we can just sit and watch....