I think Roulston captured the essence of what happened here:

"The Schaft Creek feasibility study results followed the pattern of many other large,

low grade copper-gold deposits as compared to the preliminary economic assessment

and prefeasibility study results: capital cost and operating costs are higher and

the net present value lower. Investors reacted accordingly, pushing the share price

down. The feasibility study results are positive, but far less so than the earlier studies."

I know I was attracted to the numbers in the PFS

Lesson learned.....