US stocks scored solid gains on Wednesday, spurred by encouraging remarks by politicians on averting looming tax hikes and spending cuts that could harm the economy.

The Dow Jones Industrial Average climbed 106.98 points (0.83 per cent) to 12,985.11, snapping two days of losses.

The S&P 500-stock index gained 10.99 (0.79 per cent) at 1409.93, while the Nasdaq Composite added 23.99 (0.81 per cent) at 2,991.78.

Stocks initially opened lower and continued to slide after weaker-than-expected housing data before rebounding sharply over the course of the day.

Investors digested reassuring comments by both the Democratic president and a top Republican politician.

“Fiscal-cliff chatter fuelled the market’s roller-coaster session, with optimistic comments from both President Barack Obama and House Speaker John Boehner placating the Street,” said Andrea Kramer of Schaeffer’s Investment Research.

The positive finish also followed the Federal Reserve’s Beige Book report showing that US businesses are increasingly concerned about the fiscal cliff impasse.

Hewlett-Packard led the Dow higher, gaining almost three per cent despite a Moody’s credit downgrade.

Dow member Chevron added 2.1 per cent, American Express gained almost two per cent, Pfizer was up 1.7 per cent and Wal-Mart rose 1.5 per cent.

Discount retailer Costco surged 6.3 per cent after announcing a jump in same-store sales in November and plans to issue a special $US7 ($A6.73) cash dividend per share on December 18, joining a rash of companies aiming to avoid higher dividend taxes expected to come from US deficit-slashing negotiations.

Struggling Knight Capital soared 15.2 per cent after high-frequency trader Getco offered to buy it for $US539 million.

On the Nasdaq, heavyweight Apple lost 0.3 per cent. Groupon jumped 11.6 per cent.

Bond prices climbed. The 10-year US Treasury yield fell to 1.62 per cent from 1.65 per cent, and the 30-year dropped to 2.78 per cent from 2.79 per cent.

Bond prices and yields move inversely.