SLVP holds a concentrated basket of silver mining companies in developed and emerging markets, but don't expect pure-play: its holdings just have to earn a majority of their revenues from silver mining, so you'll have exposure to companies that mine gold and precious metals, in addition to silver. The fund targets 25 companies and may extend its universe to micro- cap firms to reach this target. The index is market-cap-weighted and implements a capping methodology for diversification. It caps large and midcap gold companies to 5% then, it limits each issuer to 25% of the index, with issuers greater than 5% weight in aggregate capped at 50% of the index market capitalization. The index is reviewed quarterly starting each February.