Atonal... without tone.  That's what bond markets have been for nearly 6 weeks following the last FOMC Announcement.  While today's is not the variety that includes the press conference with Yellen or the Fed's economic projections, it still stands the best chance of anything in the near term  to set the proverbial tone.

It's not that market participants are on the edge of their seats for any particular surprise from the Fed.  Rather, this is the last FOMC Announcement where we can be sure that the rate hike isn't even on the table for discussion.  Granted, it probably won't be up for much discussion in June, but at one point in time, June was seen as the most likely month for a hike.  The point is that today's announcement will be combed for clues as to the rate hike timing in the rest of the year because it marks the end of the ineligible hike meetings.  It's a brave new world from here on out.

If the tone isn't set by FOMC, the next best option is GDP.  True, GDP data is typically pretty stale by the time it's reported, but the 'advance' report is the least stale.  It's also the first official look at any given quarter of GDP (today's report is the first look at Q1). 

Let's be realistic though...  It's not as if GDP could come in much stronger than expected and markets would suddenly forget about all the mediocre and negative data in March.  Hopefully that means we'll stay better insulated from negativity in the morning--at least as it relates to data.  Tradeflows are another matter altogether, and the harder we push past yesterday's weakest levels, the harder the pull will be from the technical abyss.