The National Federation of Independent Business (NFIB) released its small-business optimism index for the U.S. on Tuesday. The index rose to 95.2 in December from 94.8 in November.

6 of 10 sub-indexes rose last month, 3 sub-index fell, while one sub-index was flat.

"In December, Congress made expensing permanent and passed other favorable tax changes that had an immediate impact on bottom lines. However, prospects for any other substantive policy changes in 2016 are not good," NFIB Chief Economist Bill Dunkelberg said.