The exact mechanism had been discussed here a few years ago even before LN was conceived
But with LN and instant transactions, it should work like a charm. As I said earlier, I was also rather skeptic at first and thought that it was not quite possible to do. More specifically, when you buy 1000 dollars for 1 bitcoin, you obviously can't have dollars physically, but it is basically along the same lines as, for example, cash-settled futures work (so there is nothing fishy about that). You should have only 1 bitcoin locked in your account that matches 1000 dollars at the current price. If the dollar rises (say, 1 bitcoin is now worth only 500 dollars), you should have 2 bitcoins in your account to still keep 1000 dollars. If you don't have enough bitcoins, the network forcefully takes some satoshis from the account so that your balance wouldn't go negative. In the latter case, you would get what is called a margin call in trading parlance
I am not sure if you are familiar with how OkCoin.com futures works, but this sounds a lot like how their system works (although OkCoin futures are more like gambling than anything else) -- maybe with much lower leverage. With OkCoin futures, the price is generally kept in line with the market price via the fact that contracts are periodically settled at an index price (that is compiled of prices of exchanges in which actual dollars can be exchanged for actual btc, and vice versa)
No, I'm not familiar with their system. Anyway, if there is some company behind such a system, it should be taken with a grain of salt
I guess I have a few questions about this system:
1 - What mechanisms are in place to force the price on this (hypothetical) exchange to generally match the prevailing market price on other efficient markets?
2 - How do I turn my 1
BTC into $1,100 (or however many dollars 1 btc is worth) in $100 bills/cash?
3 - If those who have a USD balance (secured by BTC) on the exchange, what, from a technical perspective, would prevent the exchange from stealing the BTC that is backing the USD? If nothing, then I think there is still the problem that I described
above.
Now to your questions
1. As I understand it, there shouldn't be any such mechanism at all, i.e. the price should be determined entirely on the basis of supply and demand existing on this distributed exchange. Apart from that, how many exchanges do you know that index their price to some other exchange?
2. You can't unless you transfer the keys from your wallet to someone else in exchange for physical dollars. As I said, this is how cash-settled futures work. For example, you can buy gold futures but if they are cash-settled you can't demand physical delivery of gold after expiration. What's more, such futures make up most of the trading volume on commodity exchanges (e.g. oil and precious metals markets)
3. There is no exchange as such as you come to think of it. It is the network itself that imposes restrictions. In other words, it works in absolutely the same way as the plain vanilla Bitcoin network does, i.e. you can't spend more bitcoins that exist on the blockchain and linked to your Bitcoin address