I agree. That is this is pure speculation from my side. By the way the ratio of bitcoin volume/bitcoin market cap is only 1% right now and for litecoin we have 2%. So maybe we should get 5 ~10 times the current ratio we have for NuBits before assigning any possible causes.
What we can say for sure is that the ratio is still very low for Nu. Maybe because not so many shares in circulation and/or not so many people willing to sell or buy or bot.
I would speculate that so many people are willing to sell at those low prices.
In any case, it is an opportunity to buy more NSR.