The US labor market is leveling off after five years of consistent gains and investors are worrying about what the slowdown means for the economic future.

Hiring is slower than in recent years, the unemployment rate is no longer falling and participation in the workforce is down near a 40-year low, the Wall Street Journal reports.

Given the fundamentals of the economy, IHS Markit chief economist Nariman Behravesh says the labor market is “close to as good as it gets. But averages hide a lot of problems. A lot of low-skilled and blue-collar workers have been left behind. They might have a job, but it pays less than the job they had before the recession.”

Some economists are worried that a leveling-off labor market means hiring is falling to match weak economic growth, which slowed to a 1% pace in the first half of 2016. [WSJ]