This is confusing to me too. The best explanation I've heard is that the market is expecting a future increase in bond supply (gov bond issuance to fund coronavirus mitigation measures), which would drive prices down and yields up. This future price pressure is being priced into bonds today.
Bitcoin crashed as well and gold isn't overperforming either. So rather than having a huge transfer of assets from stocks to bonds/gold/bitcoin like we've seen during past periods of market volatility, I think we are seeing falling prices across all the forementioned asset groups.
The one open question for me is Real Estate (I work for a small commercial real estate developer). REITs are down 20%. My contacts in the Broker community have told me individual property sales transactions have dried up due to an inability to do property showings combined with no interest from buyers or sellers to make big moves until things shake out. RE moves slow so we haven't yet seen how this dynamic will impact sales prices.