U.S. stocks are likely to hit more speed bumps this week as investors become more wary of Wall Street's ability to rally further and housing starts, jobless claims and other indicators are in the spotlight.

With first-quarter earnings reports winding down and recent optimism about economic stabilization already factored into stock prices, analysts said there appears to be very little on the horizon to help extend the recent run-up.

Quarterly earnings from rival home-improvement chains Home Depot Inc and Lowe's Cos Inc may shed some light on the consumer's ability and inclination to spend. The numbers may also give a hint of any further fallout from the housing slump.

Technology bellwether Hewlett-Packard Co also is scheduled to report results this week.

But after the benchmark S&P 500 <.SPX> rose 37 percent from the 12-year closing low of early March, analysts and money managers said there is a risk that U.S. stocks may be on the cusp of a long-predicted pullback.

Economic fundamentals probably will not justify more gains in the near term.

There's been a little bit of exhaustion here, said Jeff Morris, vice president at Boston-based Standard Life Investments, which manages more than $5 billion of U.S. equity investments.

It feels like we're going to be in a phase of having to deal with some negative data points like what we saw with April retail sales. Establishing the bottom is probably more a process of a back and forth rather than just deciding things have turned, and everything will be fine.

And if the choppiness of the recent sessions is any sign, the U.S. stock market could be in for some volatile days ahead as the bulls scramble to keep the reins a little longer.

On Friday, U.S. stocks succumbed to selling of some of the market's recent high-fliers, including banks and technology, driving the S&P 500 down to close out its worst week in two months.

For the past week, the Dow Jones industrial average <.DJI> declined 3.6 percent and the S&P 500 fell 5 percent, while the Nasdaq slid 3.4 percent.

Friday's sell-off resulted in the Nasdaq breaking a nine-week winning streak.

But the Nasdaq is still up 6.54 percent for the year, while both the Dow and the S&P 500 are in the red. The Dow is down 5.79 percent for 2009, while the S&P is off 2.26 percent.

SLIGHT WARMING TREND IN HOUSING

The sparse economic calendar also is likely to make this week a troublesome one for U.S. stock investors. A major highlight will be April housing starts, set for release on Tuesday before Wall Street's opening bell. This report on housing starts and building permits will come out a day before the release of the minutes of the Federal Reserve's most recent policy meeting on April 28-29.

Economists polled by Reuters expect that U.S. housing starts rose to a seasonally adjusted annual rate of 520,000 units in April, compared with the March pace of 510,000, which was the second-lowest on record dating back to 1959.

On Thursday, the focus will be on weekly jobless claims and the Federal Reserve Bank of Philadelphia's May snapshot of business conditions in the U.S. Mid-Atlantic region. The economic data will get added scrutiny as investors look for direction and more confirmation that the recession that started in December 2007 is easing.

We're at a crossroads right now. You've got a market that's ramped up, an economy that hasn't necessarily ramped up whatsoever and so now we're into this pause, said John Schloegel, vice president of investment strategies for Capital Cities Asset Management in Austin, Texas.

It's a tug of war between the buoyant positivity that we've had for two months with the reality of the economics maybe not quite running parallel to the positive vibes on the stock market.

FROM HAMMERS TO COMPUTER HARDWARE

On the earnings front, there are several major retailers set to post quarterly scorecards, including Dow component Home Depot and Lowe's Cos.

Last week, Citigroup upgraded its rating on Home Depot's stock to buy from hold, saying it believes the earnings-per-share estimates for the top home improvement retailer may be conservative for 2009. Lowe's has reiterated its first-quarter outlook for profits and sales.

In addition to earnings from Dow component and tech bellwether Hewlett-Packard, quarterly scorecards are also expected from farm equipment maker Deere & Co , luxury home builder Toll Brothers Inc and discount chain Target Corp .

Analysts expect Hewlett-Packard's results to show fairly steady profits and sales for the quarter, but they believe investors will look at the computer and printer maker's cash flow to see how well it cushions the bottom line.

Through Friday, 91 percent, or 455 of S&P 500 companies, had reported first-quarter results, with 65 percent beating analysts' estimates, 8 percent matching them and 26 percent missing, according to Thomson Reuters data.

To be sure, some analysts said the stock market could still mount an advance ahead of the long weekend for observance of the Memorial Day holiday on Monday, May 25. But the gains will likely be fairly tepid, compared with the heady upsurge seen since March 9.

Last week, some ominous signs surfaced as volume began to slacken and investors rotated money from some of the recent winners -- technology, financials and industrials -- into more defensive areas such as healthcare and consumer staples.

(Wall St Week Ahead runs weekly. Questions or comments on this one can be e-mailed to: ellis.mnyandu(at)thomsonreuters.com)

(Reporting by Ellis Mnyandu; Additional reporting by Edward Krudy; Editing by Jan Paschal)

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