Succoth Size, page-7

A junior company doesn't need a 400 Mt low grade deposit in times when it is hard to raise money for feasibility studies and then mine development.
Drilling to reduce the tonnage to 20-50 Mt open cut with a grade around 1-1.2% Ni and 0.8-1% Cu would start to look pretty good at current metal prices.
Smaller mines are no good for BHP but good for juniors.