The Leading Economic Index, "rose sharply in December," with help from "a large improvement in initial claims for unemployment insurance," said Conference Board economist Ataman Ozyildirim.
December's gain is ahead of expectations. Economists had forecast a 0.3 percent improvement.
The index, which takes into account 10 economic components, is essentially a comparison with 2004, the year the Conference Board assigned the index a level of 100. In December, the index came in at 93.9.
"The latest data suggest that a pickup in domestic growth is now more likely, compared to a few months ago," said Conference Board economist Ken Goldstein.
Goldstein noted that improvements in the housing market will increase personal equity and improve credit scores for consumers. "However, for growth to gain more traction we also need to see better performances on new (business) orders and an acceleration in capital spending," he said.