The bond market specializes in making bets about future economic realities even as the stock market reflects shorter-term performance of the biggest companies. "Shorter-term" in this context means a heavy weight given to present day stats and an outlook that extends not more than a year or two into the future.
Bonds, on the other hand, have an outlook that lines up precisely with their stated duration. For example, the 10yr Treasury note is accounting for everything it can reasonably foresee up to 10 years from now. Sure, there is also more weight given to more immediate concerns, but even then, Treasuries tend to look farther out than stocks. They also tend to benefit from the hedging of economic bets even as stocks remain on solid footing.
The hedging of bets is an especially good idea heading into a weekend where there is still plenty of uncertainty surrounding the global coronavirus outbreaks (there are two of them, you know). The past few days have seen a bit of a surge in disconcerting headlines. No, it's still not going to be the end of humanity, but yes, it will definitely have an economic impact. Treasuries do more than stocks to account for those impacts ahead of time, and a weekend's worth of bad coronavirus news is a big enough risk to hedge bets aggressively (at least that's something we can glean from the overnight and early morning price action).
For all of the above reasons, the bond market continues to defy the broader market quite easily.
Notably, strong econ data hasn't had much of an deterring effect on the recent gains, likely because traders expect future data to more clearly show the coronavirus impact. This big rally will eventually reverse when that impact has eventually concluded (or even when it looks like it's clearly heading in that direction), but for now, it's rally time.