[fchollet]

Correct, expect arbitrage is risky in illiquid markets. Here your BTC will take a while to get into your wallet after buying them on Coinbase or BTC-e (about 10 days on Coinbase). Your wire transfers will also take a few days to clear. During these wait periods the prices of BTC will be subject to wide swings.

And at last, your arbitrage profit will get severely eaten by the fees of the banks and BTC exchange platforms.

It's never easy to make a profit in an arbitrage scheme (unless you have a crushing competitive advantage such as transaction speed): if it were easy, enough people would use the scheme, bringing the price differences back to a range were turning a profit would be difficult again... so if there are significant price differences between exchanges, it's a signal of arbitrage difficulty.

[gibybo]

I already have the Bitcoin in Coinbase though, I don't have to wait for anything. It's true that the wire transfer will take time, but the value of the dollar isn't going to change much in that time. If my only risk is the Bitcoin fluctuating in that time, it seems like free money for anyone who is already holding Bitcoin and would already be subject to that risk.