Australian bond futures prices have drifted higher following weak US housing data and ahead of comments from the head of the US central bank.

Investors are keenly awaiting Congressional testimony from US Federal Reserve chair Janet Yellen on Tuesday and Wednesday night, Australian time.

St George senior economist Janu Chan said traders will be looking for some guidance on the timing of the Fed’s interest rate hike, which is expected some time mid-2015 but but may be later.

“US treasury yields fell (prices rose), suggesting that markets are positioning for a dovish slant to Dr Yellen’s testimony,” Ms Chan said.

“Weak economic data likely helped keep yields down.”

Data from the The National Association of Realtors showed that US sales of existing homes tumbled 4.9 per cent in January.

At 0830 AEDT on Tuesday, the March 2015 10-year bond futures contract was trading at 97.505 (implying a yield of 2.495 per cent), up from 97.455 (2.545 per cent) on Monday.

The March 2015 three-year bond futures contract was at 98.150 (1.850 per cent), up from 98.140 (1.860 per cent).