Wall Street stocks finished lower Friday, shrugging off better inflation data as markets weighed fallout from a US presidential debate in which incumbent Democrat Joe Biden's performance was widely panned.

Equities had initially risen following an improving reading of the personal consumption expenditures price index, a closely-watched benchmark that boosted the odds of a Federal Reserve interest rate cut.

But yields on US Treasury rose as the day progressed, pressuring the market in the final session of the first half of the year.

The Dow Jones Industrial Average declined 0.1 percent to 39,118.86.

The broad-based S&P 500 dropped 0.4 percent to 5,460.48, while the tech-rich Nasdaq Composite Index shed 0.7 percent to 17,732.60.

Nonetheless, all three major indices are up handsomely in 2024 so far, with the S&P 500 up more than 14 percent.

Biden's performance in a debate with predecessor Donald Trump was widely criticized by observers, who said it raised concerns the president is too old to run again.

"There is a lot of speculation about what may or may not happen, but it's fair to say that some added uncertainty has been injected into the presidential race," said a mid-session note from Briefing.com.

"That uncertainty could be playing a part in the market's inability to hold on to stronger gains along with quarter-end activity."

Among individual companies, Nike plunged nearly 20 percent as it lowered its fiscal 2025 outlook citing a number of headwinds, including weaker online sales and a mixed outlook on China.

Large technology names were also under pressure, with Amazon, Microsoft, Apple and Google parent Alphabet all losing more than one percent.