Inflation-adjusted interest rates in the US have been negative before, but the dip below zero this time is different vs. recent decades: the slide is accompanied by a global economic collapse that may or may not be temporary.
It's unclear if the latest return of negative real yields will descend further, but in the current climate, the downward bias isn't easily dismissed. Perhaps the current episode will be a brief affair. That would likely require a relatively quick rebound in economic growth to something approximating normal. But with so much uncertainty weighing on the outlook,