http://seekingalpha.com/article/1185...

From the Article:

If Merrill Lynch is right and gold hits $1,500 in the next 12-15 months, that would represent a gain of about 67%. If you are invested in gold mining stocks over that same time period and history suggests leverage of 3-4 times the gain of the underlying metal, you could be looking at more than tripling your portfolio by this time next Summer. Got gold?