We could look at individual little details like the fact that the Treasury auction announcement at noon ET kept the auction amounts unchanged for the first time in a long time. Or we could just go with Occam's Razor and look at what's happening in the stock market.
One of these two lines is stocks. The other is 10yr yields. Does it really matter which when they're this correlated?
That's not to say stocks will always drive bonds. Rather, when they're this correlated and moving this much, it's clear that we're looking at a relatively frenzied "risk-off" move.
Most lenders are in a position to reprice for the better now and are simply waiting to see where this wild ride comes to a halt.