I hacked up a little arbitrage tool a couple of weeks ago which looks at the various order books and factors out some of the fees. It simulates coinbase as an exchange too, assuming that they'd honor their posted price for large purchases (may or may not be true). If anyone wants to play with it, here you go. But it's not a real 'product':
https://bitgo.com/arbitrageMy thoughts:
- As an industry, I hope all sites will stop citing MtGox prices. By doing so, we're propping up an exchange that is fundamentally broken and will be hurtful to real bitcoin users. They are broken because even if you virtually cash out there, you don't really have the money. It is not possible to withdraw in a reasonable period of time. The money is illiquid at best and gone at worst.
- I believe the run-up for MtGox prices is due to supply and demand. As the top-brand for bitcoin purchasers, new buyers are still willing to go to that site, because we're all citing it as a trustworthy place to go. However, large sellers have left because they can't have substantial funds tied up in MtGox. Even if you trust MtGox, the governments are too unpredictable to trust. This leaves us with steady demand to buy but decreasing supply -- and the prices go up.
Anyway, hope someone finds this tool useful as a mental exercise if nothing else!
Mike
