RE: share buy backhttps://tmx.complinet.com/en/display/display_main.html?rbid=2072&element_id=566
Here is a link that I found that explains one of the ways a company has to buy back shares.
Normal Course Issuer Bid (NCIB) is what they call it.
In the reading that I just completed basically the question that has to be answered by the company is "What is the most effective way to use your capital" ie is NCIB better then investing in other mining projects and or properties.