The monthly survey of the U.S. small businesses by the National Federation of Independent Business (NFIB) revealed that concerns about the U.S. economy after the partial federal government shutdown and volatility in financial markets drove a reading of small business owners' confidence lower for the fifth consecutive month. 

The conservative-leaning small-business group reported its optimism index fell to 101.2 in January from 104.4 a month earlier. Economists had expected a reading of 102, according to the WSJ's poll. 

The NFIB noted the January reading remained higher than the historical average, but hit its lowest level since the weeks prior to the 2016 elections.

"Business operations are still very strong, but small business owners' expectations about the future are shaky," said NFIB Chief Executive Juanita Duggan in prepared remarks. "One thing small businesses make clear to us is their dislike for uncertainty, and while they are continuing to create jobs and increase compensation at a frenetic pace, the political climate is affecting how they view the future."

According to the latest survey, hiring and hiring plans remained strong though some respondents were concerned about a deterioration in conditions that would support expansion.