It mostly depends on your appetite for risk. However the problem with playing arbitrage is that it works, until it doesn't and then if the coin takes off, you are left on the sidelines with only a fraction of the gains you could have realized. DarkCoin is one of the rare coins that offers true innovation development and is based around a concept getting scarcer by the minute, privacy. You never know what can happen. Just like I'm sure the the early adopter that traded 10,000 BTC for two pizzas never could have possibly imagined what they would be worth today. The way I look at it, if you make an investment that you believe in, why sell yourself short? I would hate to be like the pizza guy and BTC literally has thousands of early adopters just like him!

http://www.wired.com/2011/11/mf_bitcoin/all/1