U.S. consumers had quite the mood swing in July.

Consumer confidence hit an 11-month low in July, according to the Thomson Reuters/University of Michigan preliminary sentiment index. The index dropped to 66.5 from 76 in June, undercutting a Bloomberg News survey of economists, whose median projection was 74.

The drop could signal that consumer spending, which accounts for 70 percent of the U.S. economy, is losing momentum and could hamper the speed of recovery in the upcoming months.

“It feels like a wipeout all of a sudden,” Jonathan Basile, an economist at Credit Suisse in New York, told Bloomberg. “We’ve basically wiped out all the gains we’ve had for some time. It builds the case for moderate growth in consumer spending in the second half.”

The 9.5-point decline in the index was the largest since October 2008.

The report also showed that a record low number of Americans expected their incomes to rise in the next year. The index for consumer expectations for six months from now – which more closely projects the direction of spending – dropped from 69.8 to 60.6, the lowest point since March 2009.

Also declining was an index in the report that gauges American’s perceptions of their financial situation by asking if it is a good time to buy big-ticket items. That index dropped to an eight-month low of 75.5 from 85.6 the prior month.