By Victor Reklaitis and Carla Mozee, MarketWatch

NEW YORK (MarketWatch) -- U.S. stocks dipped Friday as Ukraine-Russia worries ramped up again. That came after a balanced speech by Federal Reserve Chairwoman Janet Yellen largely matched investors' expectations.

The S&P 500(SPX) slipped by 4 points, or 0.2%, to 1,989, while the Dow Jones Industrial Average(DJI) shed 29 points, or 0.2%, to 17,011. The Nasdaq Composite(RIXF) bucked the negative trend, tacking on 2 points, or 0.1%, to 4,534.

Barring a Friday shake-up, the three main indexes are on track to log weekly advances. Thursday's session ended with the S&P 500 marking its 28th record close this year, the Dow finishing above 17,000 for the first time since July 24 and the Nasdaq ending at its highest level since March 31, 2000. The S&P 500 is up 1.7% for the week, the Dow is up 2.1% and the Nasdaq, 1.5%.

Stocks traded roughly flat after Yellen's speech, then slumped to session lows after reports said NATO viewed a buildup of Russian forces near Ukraine as alarming, and the organization condemned the entry of a Russian convoy into Ukraine.

Careful comments in Jackson Hole: Yellen, at her speech at the annual gathering of central bankers in Jackson Hole, Wyo., said the economy is getting closer to the Fed's goals of full employment and stable inflation, and the debate at the central bank is "naturally shifting" to debating when the central bank should begin to raise interest rates. Balancing this more hawkish tone, Yellen said that 19 labor market indicators followed by the Fed suggest that the decline in the unemployment rate overstates the improvement in overall labor market conditions.

The main indexes didn't make big moves after Yellen's speech because it "pretty much" matched expectations, said Bruce McCain, chief investment strategist at Key Private Bank.

"I think the most important takeaway is that as one of the most dovish members of the board, she's clearly much less dovish than she was," McCain told MarketWatch. He said Yellen is now making "more an argument for patience rather than dovishness."

Several regional Fed presidents, including San Francisco Fed President John Williams and St. Louis Fed President James Bullard, are also offering their own views on the central bank's policies. Bullard said there is some slack in the labor market, but it isn't significant. Also set to speak Friday is European Central Bank President Mario Draghi at 2:30 p.m. Eastern. Beyond the central bankers talking, there are no major U.S. economic reports on Friday's schedule.

Stocks to watch: Women's apparel retailer Ann Inc. (ANN) posted second-quarter earnings and sales that topped analysts expectations, but offered muted third-quarter guidance. Shares fell 5%.

Aéropostale Inc. (ARO) shares dropped 9% after the clothing retailer's forecast a wider-than-expected loss for the fiscal third quarter.

Apple Inc. (AAPL) shares were up 0.6%. The company's suppliers are struggling to get enough screens ready for the launch of the bigger-screened iPhone 6 next month, according to a report by Reuters, citing unnamed sources.

GameStop Corp. (GME) shares climbed 6% after the videogame retailer's third-quarter earnings forecast outpaced estimates.

(Read more about the day's big movers here http://www.marketwatch.com/story/gamestop-soars-aeropostale-sinks-foot-locker-reports-earnings-friday-2014-08-21.)

Other markets: Oil futures (CLV4) slipped and gold futures (GCZ4) edged up. In Asia overnight, Japan's Nikkei Average broke a nine-session winning streak, and in Europe, the Stoxx 600 was lower.

Subscribe to WSJ: http://online.wsj.com?mod=djnwires

Apple (NASDAQ:AAPL)
Historical Stock Chart
From Feb 2024 to Mar 2024 Click Here for more Apple Charts.
Apple (NASDAQ:AAPL)
Historical Stock Chart
From Mar 2023 to Mar 2024 Click Here for more Apple Charts.