The issue with that arbitrage is that it was always one-sided. If you're arbing 2 equivalent markets (e.g. name trading on two different US exchanges), you'd expect to buy and sell on both markets in equal amounts, on average.
Bitstamp vs Mt Gox arb required traders to always buy BTC on Mt Gox and sell on Bitstamp (which is a strong indicator of cp risk). This makes inventory management very difficult - especially towards the end of Mt Gox where fund withdrawal times were of the order of months.
The issue with that arbitrage is that it was always one-sided. If you're arbing 2 equivalent markets (e.g. name trading on two different US exchanges), you'd expect to buy and sell on both markets in equal amounts, on average.
Bitstamp vs Mt Gox arb required traders to always buy BTC on Mt Gox and sell on Bitstamp (which is a strong indicator of cp risk). This makes inventory management very difficult - especially towards the end of Mt Gox where fund withdrawal times were of the order of months.