Has there ever been a negative feasibility study?This blog asks this question in a humorous way but it serves as a warning to be very skeptical of the feasibility studies miners put out. It also explains why often stocks do move up on fantastic improvements or refinements to PEA's. Sophisticated investors do not blindly accept these results.
And it helps to explain why companies in the penalty box, such as Nevsun, have stock prices that remain depressed in the face of promising results and studies. It can take years to get out of it and requires years of hitting your marks to rebuild faith.
https://incakolanews.blogspot.com/2017/11/the-last-honest-economic-study.html?m=1