Like GDXJ, these two funds are benefiting from momentum in mining stocks.
SILJ tracks a modified market-cap-weighted index of small-cap silver mining and exploration companies. The fund has attracted $2.27 million in total assets, and has an expense ratio of 0.69 percent. But its average trading spread is clocking in at 1.17 percent, putting total cost of ownership closer to 1.86 percent a year.
GLDX, meanwhile, tracks a market-cap-weighted index of companies engaged in the exploration of gold globally. The fund has $33 million in assets and a price tag hovering 1.22 percent a year once trading spreads are accounted for.