Something Fishy Here!, page-40

"...its in transition - and thats always a time of risk of sp weakness - same as most development stocks selloff hard 3-6months prior to a plant commissioning"

I've used that rule very successfully to make a nice living trading in mostly mineral shares.  That is when to buy low, just before the new plant turns on.  New plants using new technology are also much more productive than accounting and finance types predict (on an historical data basis) so then the earning nearly always exceed expectations/projections and the share price really shoots up.