The Dow Jones Industrial Average edged up 0.1 percent to 33,670.29, while the broad-based S&P 500 Index slid 0.5 percent to 4,327.78.
The tech-heavy Nasdaq Composite Index plunged 1.2 percent to 13,407.23.
Early on Friday, banks JPMorgan Chase, Citi and Wells Fargo posted strong results, with US markets trading higher as markets opened.
But a consumer sentiment survey by the University of Michigan released later in the morning indicated that assessments of personal finances dipped, mainly on growing concerns over inflation.
“The consumer is in worse shape,” said Edward Moya of the OANDA trading platform, adding that monetary policy could drag on the economy.
“This is not a good environment for stocks,” he told AFP.
A potential escalation in the war between Israel and Hamas has also added to market jitters.
The latest development has “triggered a wave of buying of oil and gold,” Moya said in a note.
Hamas militants shocked Israel on October 7 by breaching its southern border and killing more than 1,300 people.
Israel has killed some 1,900 people in relentless strikes on the Gaza Strip since the Hamas attack, while cutting off food, water and electricity.
The country has vowed to crush Hamas and warned Palestinians to evacuate before an expected ground offensive.
Adam Sarhan of 50 Park Investments told AFP: “The market expects it to be a very bad weekend in Israel and Gaza.”
“That Israel gave notice to the residents to leave suggests it is going to get ugly,” Sarhan said.
Among individual stocks, shares in JPMorgan Chase rose around 1.6 percent, Wells Fargo gained 3.1 percent and Citi slipped 0.2 percent.
Microsoft dropped 1.0 percent after closing its blockbuster acquisition of Activision Blizzard, whose video games include “Call of Duty.” (AFP)