Stock investors are buoying the economy. A labor market breakdown could end that

As stock market investors support economic sentiment, some economists wonder if a looser labor market could pull the rug out.

The University of Michigan's widely-followed consumer sentiment index slid more than 6% in November, nearing all-time lows and down about 30% from a year ago. Respondents were concerned that the long-running federal government shutdown would drag on the economy, according to survey director Joanne Hsu.

But at least one group bucked the sour mood: Those with the most stock holdings.

The individuals with sizable stock market wealth reported an 11% improvement in sentiment, which Hsu tied to the stock market's recent rally to all-time highs.