I don't recommend trading Juniors, personally. They're not liquid enough if you get caught in a bearish move down, and need to get out. Stick with guys like Yamana, Silver Wheaton, things like that. I trade them in my Roth, which has no tax consequences, and it's a dandy way to pile up gains without having to lose a piece to taxes.

Also, on the way up, juniors also run out of buyers. Liquidity exhaustion creates a lot of slippage.