Hecla Mining shareholders are down 26% for the year (even including dividends), but the market itself is up 31%. However, keep in mind that even the best stocks will sometimes underperform the market over a twelve month period. On the bright side, long term shareholders have made money, with a gain of 12% per year over half a decade. If the fundamental data continues to indicate long term sustainable growth, the current sell-off could be an opportunity worth considering. I find it very interesting to look at share price over the long term as a proxy for business performance. But to truly gain insight, we need to consider other information, too. For instance, we've identified 1 warning sign for Hecla Mining that you should be aware of.