Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of precious-metal miner Endeavour Silver (NYSE: EXK) weren't looking too shiny today, as they slumped as much as 12% in intraday trading.

So what: This morning, Endeavour announced earnings for its first quarter, and the numbers looked pretty darn good. Revenues jumped by 94% year over year to $35 million, while adjusted earnings rocketed from $1.1 million last year to $14.5 million. On a per-share basis, the company registered a $0.18 profit, which was easily better than the $0.12 that Wall Street was expecting.

Now what: With results like that, why in the world would shares be down today? A key driver for the company's profit gains was the 96% increase in the realized silver price versus last year. Over the past week, though, silver has taken a beating, as evidenced by the explosion of volume for the iShares Silver Trust (NYSE: SLV) and its 26% drop since last Thursday. When your revenue relies heavily on the price of silver -- as is the case for Endeavour -- this is not an encouraging development.

Want to keep up to date on these stocks?