http://online.wsj.com/articles/with-a-bitcoin-etf-risk-isn-t-virtual-1410120108

Some wealthy investors are already buying into a trust that tracks the average dollar price of the virtual currency. And the firm behind that trust is racing one other to bring bitcoins to the masses in the form of a publicly traded fund.

Bitcoins were worth about $10 each less than two years ago, then more than $1,100 a few months later, and now trade around $475.