I see no reason to buy. This stocks is very weak. All it does is decline. If Silver does not go up, they will run out of money and production will be stopped. And the stock will fall under $10.
What buy signal? Time to take your losses. Now or at 17? How much pain can you tolerate. Try using a 10% stop loss. Buy on weakness and limit your losses. Another trick. Only buy stocks over their 50-day mvg.avg.
It's pretty simple. But you wouldn't be in the pickle you're now in.