U.S. stock futures were modestly higher ahead of the opening bell.
Yellen is expected to be nominated by President Obama at 3 p.m. ET. She has long been a favored candidate for the position and shares much of current chairman Ben Bernanke's thinking on loose monetary policy.
"News that Obama is set to nominate the dovish vice-chair Janet Yellen to the top job at the Fed has seen sentiment improve, based on the prospect of policy continuity," wrote Mike van Dulken, head of research at Accendo Markets, in his daily note to clients. "It's expected that rates will stay low for longer and policy will be accommodative."
An hour before the Yellen announcement, investors will get a look at the minutes of the Federal Reserve's most recent policy meeting. The document will be closely scrutinized for clues about the central bank's plans for its bond-buying program.
Earnings rolling in: Alcoa (Fortune 500) shares rose nearly 4% in premarket trading after the aluminum producer's earnings beat expectations. ,
Costco (Fortune 500) missed on revenue and reported a slight bump in same store sales. Earnings per shares came in better than expected. ,
Retailer Family Dollar (Fortune 500) beat earnings forecasts, while revenue was roughly in line with estimates. ,
The yield on one-month Treasury bills surged to its highest level since the financial crisis Tuesday as investors worry about the country's ability to pay its short-term debts.
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|Overnight Avg Rate||Latest||Change||Last Week|
|30 yr fixed||4.26%||4.48%|
|15 yr fixed||3.30%||3.31%|
|30 yr refi||4.25%||4.45%|
|15 yr refi||3.29%||3.34%|
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