For the fourth week in a row, all three of the major U.S. stock indexes have risen. Over the past five days, the Dow Jones Industrial Average (^DJI -0.98%) moved higher by 1.56%, or 235 points, and now sits at 15,354. The S&P 500 rose 1.98% and is now just above the 1,666 mark, while the Nasdaq increased 1.81% and is just 2 points below the 3,500 mark.

It seems nothing can stop or even slow down the markets. On days when positive economic data is released, stocks climb higher. But when negative economic data hits investors, the markets just slightly move lower and sometimes turn positive by mid-afternoon once the sting of the poor data wears off. So the best thing investors can do at this time is sit back and enjoy the ride higher, but prepare themselves mentally for a pullback and don't panic sell when it happens.

Before we hit the Dow losers, let's look at the index's big winner of the week: Cisco (CSCO -0.52%). The technology networking company announced earnings after the closing bell on Wednesday, and on Thursday alone, shares rose 12.62%. But over the past five trading sessions, Cisco's stock price increase by 14.88%. Cisco posted revenue and earnings per share that both beat what analysts were expecting. Furthermore, sales growth in developing nations was very strong and easily made up for the declines seen in Europe and other slowing markets.  

The big losers
This week's worst Dow performer was Intel (INTC 1.77%), which fell 1.79% during the past five days. On Monday, the share price declined after a Bernstein Research report highlighted a number of issues the company will face in the future, such as lower PC sales and revenue, while increased R&D spending will be need to adequately compete in the mobile market. In addition, a report from Gartner that highlighted weak PC sales in Europe sent Intel's shares mildly lower during the week.  

While the Gartner report hurt Intel, it hammered Hewlett-Packard (HPQ 0.11%). The report indicated that HP personal-computer sales fell 32% in Europe during the first quarter and sent shares lower by 2.56% on Wednesday. Investors also fled the stock after Dell came out with a poor earnings report, as investors fear that HP will post similar results on May 22.

But not all news was bad for HP this week. On Thursday, shares moved higher by 1.86% after the company's newest tablet/laptop received positive reviews. HP is offering a tablet that comes with a keyboard as part of the purchase price, as opposed to the a- la carte options we've seen from the other tablet manufacturers. Still, the negative moves this week outweighed the increases, and shares ended last week lower by 1.25%.

Finally, shares of Wal-Mart (WMT 0.57%) declined 1.29% this past week, after the company announced earnings for the first quarter. Wal-Mart posted revenue of $114 billion, while analysts were expecting $115.8 billion. Earnings per share came in at $1.14, with estimates sitting at $1.15 per share. Although the company did miss on both the top and bottom lines, EPS increased by 5% from the same quarter a year earlier, and the company is having to deal with the payroll-tax increase, the sequestration, and delayed income-tax returns for a large portion of its customer base.

Investors should also consider a number of quarterly results before buying or selling -- for Wal-Mart and any other company -- and remember to not make rash decisions after just one announcement.  

Other Dow losers this week: