Will GDP finally be the piece of economic data that actually moves markets?  No...  but it might play that role on TV.  I'm serious actually. 

Markets are very likely going to go where they're going to go today regardless of the GDP reading.  But if that reading supports those trading goals, it will almost certainly be used as cover to facilitate the movement. 

GDP doesn't matter in this case for the same reason that the final revision of any GDP reading tends not to matter: this data is from 3-6 months ago!  Not only that, but it's really only the first reading of any given quarter of GDP that has legitimate surprise value.  Forecasters are much better at adjusting calculations for the subsequent revisions after the initial reading is out.

Even if GDP manages to matter to some small extent, there are more relevant market movers behind the scenes.  These include European bond markets, quarter-end trading needs, tactical trading based on technical levels, and the stock lever.  The latter has been highly connected this week.  Take a look:

As far as tactical trading and technical levels, this refers to the portion of the investment community that doesn't necessarily need to buy or sell bonds, but that does so in order to make a profit in the short term.  10yr yields broke below their middle Bollinger Band yesterday (21-day moving average and the middle blue line below) and stoked bullish fires in other mainstream technical studies. 

Another day of gains would solidify the trend and act as a positive indicator for Monday and Tuesday (last 2 days of the quarter).  At that point, we could see significant adjustments on Wednesday--not only because it's a new quarter, but also because an ECB meeting and NFP follow shortly thereafter.