The S&P 500 rose slightly on Friday and saw its best week in about three months as investors continued to propel equities near four-year highs.
Two slightly softer economic reports curbed broader gains, keeping both the Nasdaq and Dow, which has risen for seven straight sessions, near break-even territory. Both indexes closed lower.
The benchmark Standard & Poor's 500 index has risen 2.5 percent this week in its best weekly performance since mid-December.
Investors, buoyant over the economic outlook, have pushed the S&P above 1,400 to its highest level since May 2008 after a surge of almost 30 percent from its low in October.
Energy shares were the big gainers of the day. Crude prices advanced on continuing tensions over Iran's disputed nuclear program and the potential for supply disruptions in the region.
"Fundamentals are improving, corporate profits are rising, and the market has really good upward momentum," said Stephen Wood, chief market strategist at Russell Investments in New York, which has about $140 billion in assets under management.
"I think we still have room to rise, but that said, we're keeping an eye on oil, which could be a destabilizing factor if it gets too high."
The Thomson Reuters/University of Michigan's preliminary reading on the overall index on consumer sentiment slipped to 74.3 from 75.3 in February, shy of economists' forecasts for a gain to 76.0 as climbing energy prices pushed inflation expectations higher for next year.
Separate data on Friday showed factory output edged higher last month, despite a fallback in auto production. However, overall industrial output was flat, held back by a second straight monthly decline in mining activity.
Elsewhere on the economic front, the Labor Department said its Consumer Price Index increased 0.4 percent last month after advancing 0.2 percent in January, matching expectations, while inflation pressure, measured by the core CPI excluding food and energy, remained subdued.
Credit Suisse analyst Andrew Garthwaite raised his year-end 2012 target on the S&P 500 to 1,470 from 1,400, noting "equities are now 9 percent above their six-month moving average - but when this has happened, equities have typically risen by 7 percent over the following six months."
The latest round of economic data, although softer than hoped, did little to dent that thesis, though some remained leery that equities could be ripe for a pullback as the CBOE Volatility Index or VIX remains near lows not seen since 2007.
This week marks the quarterly expiration and settlement of March equity futures and options, an event termed "quadruple witching," which could increase volume and volatility.
Apple Inc edged up as its new iPad proved to be another hot seller on Friday, as expected. Hundreds of iPad fans lined up at stores across Asia to be the first to get their hands on the tablet computer.
Several banks, including Goldman Sachs Group, have shown an interest in buying American International Group Inc's complex and troubled assets tied to the insurer's bailout, the Wall Street Journal said, citing people familiar with the matter.
Reuters contributed to this report.