The University of Michigan's preliminary consumer sentiment index fell to 47.8 in September from 51.7 in August, larger than an expected decrease to 51.0 in a survey compiled by Bloomberg.
The current conditions index decreased to 50.9 in September from 51.9 in August, while the expectations reading declined to 45.8 from 51.5.
"With a resurgence in fuel prices and trade tensions, consumers anticipate greater pressures on their pocketbooks to come," Michigan said. "Five-year expected business conditions remained stable at readings well below their historical average, suggesting that consumers believe that emerging risks this month may not have further worsened the long-run outlook."
Respondents saw one-year inflation expectations at 4.6%, up sharply from 4.0% in August, while five-year inflation expectations increased to 3.4% from after three straight months at 3.3%
The twice-monthly Michigan Sentiment index measures consumer sentiment early in the current month (the preliminary estimate) and is then revised later in the month (the final estimate). The headline index is a combination of the current assessment and expectations for the near future.
An increase in the reading suggests consumers are more confident, a positive for stocks if that confidence translates into spending. Increased demand is usually inflationary, a negative for bonds.