RE:Question about gdx/gdxjKey Features Size and Liquidity Requirements Full MCap of at least 150 mln USD. Three month average-daily-trading volume of at least 1 mln USD at a review and also at the previous two reviews. At least 250,000 shares traded per month over the last six months at a review and also at the previous two reviews. Pure-Play Companies have to generate at least 50% revenues from gold or silver mining. Diversification Company weightings are capped at 8%. Review Quarterly.