Heading into the French election at the end of last week, we knew that Le Pen (the candidate who likely would have helped the bond rally continue) probably wasn't going to win, but that there was a small chance. As such, markets could MOSTLY price in a Macron victory (the candidate who would likely result in bond market weakness). While Macron didn't win outright, he did advance to a run-off that he's widely expected to win.
Some of last week's bond market losses were due to pre-election polls predicting this result. It stood to reason that there would be a bit of extra bond selling to do once we had confirmation that Le Pen wouldn't win.
Although the selling classified as more than "a bit" at first, these reactions to overseas events often die down in US trading hours. That's exactly what happened today. Interestingly enough, US bond markets went almost perfectly flat after European trading was done for the day.
With the runoff not happening until May 7th, domestic considerations return to center stage. Key among these is the scheduled tax reform announcement on Wednesday afternoon as well as various "government shutdown" headlines that are sure to surge as the week progresses.