Quote from: Gavin Andresen on October 25, 2011, 01:46:25 AM

Quote from: zhoutong on October 24, 2011, 03:12:56 PM

There's nothing wrong with trading Bitcoins, just like there's nothing wrong with exchanging USD to EUR to buy a glass of wine.

Yes, but if you are spending a lot of time or effort trying to make money on an essentially unproductive activity

Speculating can be a productive activity, if done right, that is, if speculators manage to guess correctly the future price movements. A speculator that make mistakes in such guesses make things slightly worse, though. Obviously, nobody has more incentives to make it right than the speculator himself.
http://www.thefreemanonline.org/columns/the-benefits-of-speculation/
http://wiki.mises.org/wiki/Speculation

That's just part of a more general rule actually. If you study praxeology and economic science you'll understand that any activity that brings profit without violating any property right (directly or indirectly) is productive.