Possibly ask yourself a few questions here; is the business an...

Possibly ask yourself a few questions here;

is the business an ongoing concern (access to funding/cash at hand...etc)?
has evidence of the geology changed?
has the method/cost of production changed?
has the price of the product changed?
has the market for the product changed?
has the market valuation of the business changed?

If your answer to the first and last question is 'yes', and the others are 'no', then "the market" is wrong, or knows something that we as "investors / gamblers" do not.
Good luck All.