With an ounce of gold commanding more than $1,730 these days, it may come as no wonder for readers to discover a gold miner on this week's IBD Big Cap 20. However, the presence of such stocks -- or any stock, for that matter -- does not mean that they deserve an automatic entry ticket into your portfolio. Why? Gold stocks carry unusual risks. For starters, the companies' fortunes depend so heavily on what the price of the commodity itself is doing.