There are a number of things in play which could point to a possible sell off.
1. Volume spike blow off at recent high 2. Ascending triangle - bearing pattern 3. Break out failure/bull trap at recent high 4. Divergence on 3/10 Oscillator
It doesn't seem logical that bonds could sell off here, but on the basis of the above, there is only one thing to follow, and that is price.
Gold is displaying the same sort of behaviour. I will do another chart on that.
If bonds and gold fall, it would only give possible strength to the argument for more upside on the futures indices.