I'm looking forward to a time when the top 10 bitcoin exchanges handle no more than 10% of the trade each and meta-exchanges like bitfinex allow you to take advantage of the liquidity on all of them.
I'm really curious how you manage to have fiat on the right exchanges at the right time though, especially now that you are handling two third party orderbooks. Would you care to shine some light on that?
Sure. First we begin to have enough assets to put a lot in the two exchanges while keeping the rest safe in our cold wallet and bank account.
Secondly, if there is a shortage of funds in one of the exchanges, you will not be able to buy (if its a USD shortage) or sell (if BTC shortage) on this exchange, until the shortage is gone. Simple as that.
When this happen on Mtgox, you will get a "NO RESERVE" error and the order will stay pending. When this happen on Bitstamp, Bitstamp orders will simply be ignored and the order will be executed on BFX or Mtgox. THis behavior may change in the future depending on respective volume.
Now our job is to make sure there is always enough balances on all third party exchange
1) Are fee rebates of MtGox (or Bitstamp) passed through?
2) Why do I have only BFX as a routing choice? The FAQ states: "You can choose to execute your orders only on mtgox, or only on bitfinex, for example; that's the routing feature."
1: We have our own fee schedule. For Bitstamp we don't want to make too much competition, for Mtgox the fees allow us to deal with requotes which happen a lot with them (due to them caching their orderbook and not wanting to give us real time access even though we are ready to pay high for it and make quite a high percentage of their trading volume. They just don't give a fuck).
2. I added Bitstamp routing option, Mtgox may come later.
I have some cleaning to do in the FAQ and explanations pages
Have a nice day
Raphael
Bitfinex team