The S&P 500 closed slightly higher on Friday, with trading choppy toward the session's end and all three of Wall Street's major averages showed weekly declines as investors worried about interest rates and waited tentatively for upcoming US inflation readings.

The S&P 500 gained 0.1 percent to end at 4,457, the Nasdaq Composite gained 0.1 percent to 13,761. The Dow Jones Industrial Average rose 0.2 percent to 34,576.

Investors worried about rising oil prices and they have been fretting ahead of the Consumer Price Index (CPI) for August, due on September 13, seeking signals about the Federal Reserve's future policy decisions on interest rates.

While traders are betting on roughly 93 percent probability the Fed keeps rates at current levels, after its next meeting ends on September 20, they are pricing in a more divided 53.5 percent chance for another pause at the November meeting, according to CME FedWatch Tool.

A move higher in US 2-year Treasury yields probably pressured stocks, but investors have been concerned about rising rates since early August, said David Lefkowitz, head of US Equities at UBS Global Wealth Management. "The tone has changed in recent weeks because of the move up in rates. People are questioning whether this is a risk to economic growth. Are higher rates going to lead to some slow down in conjunction with the dwindling of excess consumer savings," said Lefkowitz, who also cited concerns about high equity valuations.

Oil prices are up so far in September and on track for a fourth straight monthly gain, and this week's data also fueled inflation fears. This included stronger-than-expected services activity data and a fall in weekly jobless claims.

"My expectation is that the CPI print could come in higher than expected (with) the price of oil pushing higher," said Phil Blancato, chief executive officer of Ladenburg Thalmann Asset Management.

"We have a problem where ultimately the Fed may be pushed into a corner, and while they might take a pause because of the lag effect, I don't think they're done."

Mixed comments from Fed officials have added to uncertainty. New York Fed President John Williams kept his options open, while Dallas Fed President Lorie Logan said though it "could be appropriate" to keep rates steady at the next meeting, more tightening might be needed. (Reuters)