A measure of U.S. consumer sentiment posted its steepest three-week slump since 2008 as optimism tumbled among lower-income Americans, a sign that economic strength may be failing to persist more broadly throughout the country.

The Bloomberg Consumer Comfort Index tumbled to a nine-month low of 58 in the week ended Nov. 10, according to data released Thursday. All three components declined, with views of the economy the lowest since June 2018, assessments of personal finances the weakest since January, and the buying climate gauge the lowest since June.

The broad weakness signals that consumers, who have been supporting the longest U.S. expansion on record, may be growing more concerned despite the strong labor market and record stock prices. Uncertainty about trade policy has been lingering and global growth is projected to remain sluggish.

The downbeat comfort data contrast with other surveys offering more optimistic readings of the mood among Americans. The University of Michigan sentiment survey rose in November for a third straight month, while the Conference Board’s confidence index has weakened somewhat but remains near historical highs.

Comfort for those making less than $50,000 decreased for a 10th straight week, extending the longest streak of declines in data since 2010. While the stock market has done well, those who are less well-off probably aren’t feeling the gains, according to Gary Langer, head of Langer Research Associates, which conducts the weekly survey for Bloomberg. The S&P 500 Index closed at a record Wednesday, extending its advance so far this year to more than 23%.

The declines in consumer comfort, “initially focused on lower-income households, have now been expanding in recent weeks to middle-income households,” he said in an interview. “Better-off folks are still well insulated.”

The composition of the report showed several categories were the lowest in at least a year, including for men, ages 18-34, the Midwest, black Americans, renters and people separated, widowed or divorced. The reading for part-time workers improved for the first time in three weeks.

This article was provided by Bloomberg News.