GDP doesn't usually move markets as clearly as it did today, but today was a bit of an anomaly. First off, we'd been waiting for this revision longer than normal due to the shutdown. Beyond that, it was a fairly sharp revision forecast due not only to the shutdown, but to the other economic uncertainty that crept in during the end of 2018. Finally, it carried asymmetric risk due to widespread expectations for the actual number to come in even farther below the 2.3% forecast.
With all of the above in mind, the 2.6% result (accompanied by a 2.0 vs 1.7% reading on the deflator, an important inflation metric) was enough to put bond traders in a defensive mood at the outset. By the time Chicago PMI came out strong enough to erase last month's disconcerting slide, everyone was looking to sell.
In outright terms, today's weakness isn't that severe, but when taken together with yesterday's move, it presents a case for a broken consolidation range after more than a month of fairly perfect behavior. Such breakouts must be taken seriously until we see data and trading that counteracts today's damage. Tomorrow may be up to the task. There's a healthy slate of data, but ISM Manufacturing is the biggest potential market mover at 10am. Whether or not it "counteracts" today remains to be seen. At the moment, forecasts call for a decline from the previous month, just like Chicago PMI did today, before handily crushing that forecast.