The GDX token is an ERC-20 token which uses a Fixed Supply contract. This means that 4,901,960,000 GDX will be created in a single token generation event, and then distributed in the GDX token sale.
All unsold tokens will be provably burned.
GDX cannot be mined. Individuals who wish to acquire GDX at a predictable price would be best served to purchase it from the public token sale.