In recent days, there has been unusual options activity in iShares Silver Trust ETF (SLV). SLV is the one of the most popular ways for investors to trade silver. Precious metals have become a popular investment lately as interest rates return to ultra-low levels. Gold has seen quite the run higher, and as it gets more expensive, investors could shift their focus to silver. With SLV just under $17 per share, more than 40,000 of the 17 calls were purchased, which expire in February. This suggests that silver could be moving higher over the next month.