US stocks ticked lower in early trading on Friday in a light day on the economic calendar, but the S&P 500 and Nasdaq were on track to close their eighth positive week in the last nine.
The S&P 500 has traded in a tight range in the past two weeks, mostly holding on to gains of nearly 9% since the beginning of the year.
S&P futures could close their ninth straight week of gains, the longest such run since one ending January 2004.
"This has been a straight up move in prices, and it is unusual for that to continue," said Rick Meckler, president of investment firm LibertyView Capital Management in New York.
"In order to avoid [a pullback] we need a continued flow of good news, and there aren't many earnings forecasts coming in right now, which could be the next push," Meckler said. "People will focus on possible negatives, and right now the biggest out there is oil prices."
Energy shares were the largest weight on the market. US crude oil futures fell more than 1% to under $108 a barrel a day after hitting a 10-month high above $110 on supply concerns in the West Asia.
The concern is a steep rise in crude and gasoline prices will cut into consumer spending and hurt the economic recovery.
Aides to US President Barack Obama and Israeli Prime Minister Benjamin Netanyahu are scrambling to bridge differences over what Washington fears could be an Israeli attack on Iran's nuclear sites, a concern at the heart of the recent spike in oil prices. Both leaders will meet on Monday.
The US dollar's strength against the yen and the euro could continue to pressure oil and other commodity prices.
The Dow Jones Industrial Average dropped 21.46 points, or 0.17%, to 12,958.84. The S&P 500 Index lost 2.46 points, or 0.18%, to 1,371.63. The Nasdaq Composite fell 1.72 points, or 0.06% to 2,987.25.
Yelp Inc's initial public offer priced at $15 a share, above the expected price range, valuing the US consumer review website at nearly $900 million.
Yelp shares opened at $22.01 and traded as high as $26, up 73.3%.
US food and drink maker Sara Lee Corp will pay a special $3 dividend after it completes the spin-off of its coffee and tea business, expected by the end of June. Shares rose 5% to $21.41.
Shares of Shutterfly Inc jumped 16.5% to $31.36 after bankrupt Eastman Kodak agreed to sell its online photo services business to Shutterfly for $23.8 million.
