I'm just speculating of course, but I don't think this year's tax loss selling is as severe as last year's (if you don't have capital gains, you don't need capital losses), but there must be some portfolio embarrassment selling. Who wants to admit they own these dogs? Year end is also a typical time to do some housecleaning - take out the trash from the portfolio.
Still, I haven't noticed that much extra selling - the whole year has been dreadful for the juniors. There just hasn't been much buying. Buyers usually come in to these (and US small caps as well) around mid Dec. I think that will happen again, but probably not as good as last year's 20% gain in Venture.