By Corrie Driebusch 

U.S. stocks ended slightly lower Friday, capping off a week of low trading volumes and no market-moving catalysts.

The week was slow, with the fewest shares changing hands on Friday since December 30. On Friday 4.89 billion shares changed hands. The average so far this year is 6.58 billion. The stock market will be closed Monday for Memorial Day.

"Volumes have been anemic," said Neil Massa, senior equity trader at John Hancock Asset Management. "But the trend seems to be higher. Even on days with pullbacks it seems to be healthy consolidation."

Stocks spent most of Friday in the red, though they pared some losses after Federal Reserve Chairwoman Janet Yellen reiterated the central bank's intention to raise short-term interest rates this year.

The Dow Jones Industrial Average fell 53.72 points, or 0.3%, to 18232.02. The S&P 500 declined 4.76, or 0.2%, to 2126.06 and the Nasdaq Composite shed 1.43 points, or 0.03%, to 5089.36.

For the week, the Dow slipped 0.2%, while the S&P 500 added 0.2% and the Nasdaq Composite gained 0.8%. Both the Dow and the S&P 500 hit fresh record highs earlier in the week.

As first-quarter earnings season draws to a close, investor focus is largely back on the timing of any interest-rate increase by the Federal Reserve, traders said.

Many investors expect the Fed to increase rates in September, but there is little consensus as to whether slightly higher borrowing costs will derail a bull run that is in its seventh year. In her remarks Friday, Ms. Yellen also emphasized the economic headwinds such as slow wage growth, low inflation and disappointing growth, discouraging the view that the Fed would embark on a full-fledged tightening cycle.

Ms. Yellen's remarks Friday didn't provide new clarity for investors.

"She didn't say much that's new," said Paul Christopher, head of International Strategy, Wells Fargo Investment Institute. The tone, he said, suggested she continues to believe rate hikes this year are appropriate and that the decision will be data dependent, not new revelations.

"The speech leaves the markets still churning, looking for an event or a time or magnitude for the Fed to move," he said.

Earlier Friday the Labor Department released a stronger-than-expected reading on inflation in April.

The consumer-price index rose 0.1% in April from a month earlier, the Labor Department said Friday. Excluding the food and energy categories, so-called core prices gained 0.3%, the largest increase since January 2013. Economists surveyed by The Wall Street Journal had expected overall prices to increase 0.1% and core prices to rise 0.2%.

Federal Reserve officials are watching for signs that inflation is picking up as they debate when to raise short-term rates for the first time since June 2006.

In Europe, Germany's DAX slipped 0.4%, while France's CAC 40 edged down 0.1%.

In commodity markets, gold futures shed 0.01% to $1204.30 an ounce. Crude-oil futures lost 1.6% to $59.72 a barrel. The yield on the 10-year Treasury note was at 2.211%, compared with 2.186% on Thursday. Yields fall as prices rise.

In corporate news, Deere & Co.'s shares rose 4.4% after the farm-equipment producer reported its profit dropped in the latest quarter though results were still better than feared.

Campbell Soup Co. reported its profit easily topped expectations in the latest quarter as the company began implementing cost-cutting plans. Shares rose 2.1%.

AĆ©ropostale Inc. shares tumbled 15% after the teen retailer projected a wider-than-expected loss for the July quarter.

Write to Corrie Driebusch at corrie.driebusch@wsj.com