Risk aversion pushed the 30-year Treasury to a multi-year high overnight and equities are tumbling hard even after a substantial fall on Monday. 

"Ongoing worries about Europe, talk of a bigger haircut on Greek debt (probably inevitable), Goldman Sachs calling for recession in Europe, and a brewing U.S.-China trade war are all weighing on markets," said BMO Capital Markets. 

The 30-year yield is a basis point lower at 2.71% in early trading, while the benchmark 10-year yield is a basis point down at 1.74% and the two-year yield is steady at 0.24%.

S&P 500 futures are down 13.1 points at 1,075, reflecting a 1.21% drop, and Dow futures are 109 points lower at 10,420, a 1.04% fall.

In the last three months, the S&P has shed 240 points, or 17.95% of its value.

Global markets suggest equities could be in for a rough session. Shares in Japan and Hong Kong fell 1.1% and 3.4%; in Europe the DAX is off 3.2%, the CAC-40 is down 3.3%, and the FTSE 100 is 3.4% lower.

Little new data is available to change market sentiment, so Fed chairman Ben Bernanke will have a lot of viewers when he speaks at 10am. 

Key Events Today:

10:00 - Fed chairman Ben Bernanke gives a talk before a bipartisan congressional panel on the U.S. economy.

10:00 - Factory Orders should show a minor slowdown in August of 0.1% following a  transportation-led 2.4% jump the month before. The already-reported 0.1% fall in new orders for durable goods provides most of the ket data for this report, yet forecasts range from a 1% decline to a 1.1% jump, so there's room for a surprise.

"Orders held up surprisingly well in the advanced notification of durable goods orders in August, which sets the tone for factory orders," said Nomura Global Economics. "Price weakness from falling commodities over the month, however, should limit the upside for nondurable inventories and orders. We forecast an increase of 0.1% in August factory orders, with inventories increasing by 0.5%."

• Treasury Auctions:
• 11:30 - 4-Week Bills