Jeff is a fairly good stock picker that is for sure.
Right now nobody knows why the gold producers and miners are selling off like they are. Just doesn't make a whole lot of sense relative to the Price of Gold.
A junior like Corvus is considered a high risk beta stock with large volatility. This is an excellent bet in the gold mining explorer but investors must keep in mind that it will swing wildly in both directions with a general trend of upward bias.
The best time to get in is before discovery and the second best time is when the stock sells off from its peak just as it is raising capital for starting its mill. There will be a long quiet period at a depressed price where nothing much will be going on except for the construction of the mill.
Corvus will be a great bet next summer. In the meantime expect volatility in both directions.