"There's a reasonable amount of concern out there about the general direction of the global economy," said Ian Lyngen, senior Treasury strategist at CRT Capital.
Events in Ukraine were also a concern, sending buyers into gold, as investors await the Sunday vote in Crimea on whether to join Russia and abandon Ukraine.
Bond yields were lower Tuesday, but the three-year edged higher. The Treasury's $30 billion three-year note auction was lackluster, and Lyngen expects 10-year yields to rise into the 1 p.m. ET auction of $21 billion in 10-year notes.
(Read more: What could heat up gold prices this week)
The 10-year was yielding 2.77 percent in late trading Tuesday. The Dow fell 67 points to 16,351, and the S&P 500 fell 9 to 1,867.
Markets have been watching every bit of economic data, in an attempt to glean whether the string of weaker data are the result of unusually severe winter weather or something else. Every bit of employment-related data are even more scrutinized because of the potential impact on the Fed's decision to cut back on its bond-buying program.
The Fed meets next week, with Fed Chair Janet Yellen presiding for the first time and conducting the post-meeting press briefing.
"Is anyone worried about the Fed? No, they're going to taper," said Lyngen.
(Read more: Stock market in 'euphoria mode': Citi strategist)
There are a few reports for markets to watch Wednesday. There are mortgage applications at 7 a.m. and oil inventories at 10:30 a.m. There is a release on the federal budget at 2 p.m.
"You do have auctions. That's what's driving the week, and the 10-year tends to be the most important of the week, and that will probably drive things tomorrow," said Ward McCarthy, chief financial economist at Jefferies. "The (bond) market has been trading well so far this week, which makes it look like it's going to be difficult to bid on this baby. We continue to see buying."
McCarthy said a lot of big bond market investors were caught short. "There are a lot of real money accounts that are gradually trying to get their positions a bit more balanced," he said.
Several earnings releases are also Wednesday expected from Express, Krispy Kreme, Vail Resorts and Williams-Sonoma.
—By CNBC's Patti Domm. Follow her on Twitter @pattidomm.