At first it is pretty funny to look for stability in crypto market. Moreover, ETH was stable, but then it went down and I doubt somebody now can call it stable
For me personally, the most stable coin is Bitcoin, not your ethereum. More precisely, it is not even yours, but Buterin. If his team had made an upgrade last year in the spring, perhaps there would not be a fall. And so, what we see ... Ether fell before Bitcoin, and then with Bitcoin. As for QUSD: I personally judge this token early, because I have not seen it on popular exchanges. If they manage to achieve maximum visibility, then success will be.