The healthcare bill is all anyone can talk about (here's one recent article from Reuters).  We rarely see such an abrupt coalescence of market focus on something that was heretofore "off the radar."  There are a few potential reasons for this.

First, the realization that the healthcare bill was such a priority for the administration is fairly recent.  We knew Trump wanted to repeal/replace the Affordable Care Act, but we didn't know those efforts would take precedence over tax reform until late last week.  

This week saw rapid and constant evolution of the status of the bill, its likelihood of passage, and its implications.  At first, it was a non-starter that couldn't get enough support from conservative republicans led by Mark Meadows and the "Freedom Caucus."  

From there, news came out of closed door meetings with Trump issuing ultimatums to the holdouts and thinly-veiled threats to Meadows.  Pundits began to change their tune and suddenly, we were entertaining the possibility that a bill might actually pass.

If the bill passes, it will be important to see how it changed from its original form in order to lock-up more votes.  It will also be important to see who made which concessions and how big those concessions were.  If that analysis doesn't suggest that the Trump administration had to give up too much ground, it would be a tremendous vote of confidence (stunning, actually) in his ability to push other legislation through.  This would very likely be very bad for bond markets.

Today begins with the promise of a procedural vote to be held by 11:15am ET.  If that goes well, A bill could be passed before the close of business today.  Significant volatility would be almost guaranteed.