My take : it's because of the Feasibility.....it shows a lot of positive things down the pipe....but kinda brings reality into the forefront....by showing timelines etc., it becomes clear that this will take months and years to happen.
This blunt hit of reality kicked the momentum out of the shareprice and we are (obviously) getting a correction.
There are many charts showing the history of shareprices on Juniors as they progress from explorers to producers and it isn't pretty.
Maybe some were expecting a takeover or something more sudden.
Just my opinion,
Red