Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

The three-week September rally is over. After gaining 640 points, or 4.33%, during the first three weeks of the month, the Dow Jones Industrial Average (^DJI 1.05%) ended this past week down 192 points, or 1.24%, pulling September's total monthly return down to a mere 3.02%. The move comes after the index changed three of its components to start the week and uncertainty about the debt ceiling and a possible government shutdown loomed in investors' minds.

But despite the generally negative sentiment moving throughout the markets this past week, the S&P 500 and the Nasdaq finished the week split -- with the S&P 500 down 1.06% and the Nasdaq higher by 0.18%.

Before we jump into the big losers of the week, let's quickly look at the Dow's top performer of the week: new component, Nike (NKE 0.22%). Shares of the footwear specialist rose 6.15% this past week, after the company reported stellar quarterly earnings on Thursday following the closing bell. The company was expected to report $0.78 per share in earnings but managed to post $0.86. Revenue also beat expectations, after the company reported an 8% sales jump. These results came even as China still represents a weak spot for the company, but as shocking as it may sound, Europe and the U.S. were shining stars.  

Last week's big losers
While one of the new Dow components became the index's best performer this past week, another newbie was the worst performer, as Goldman Sachs (GS 1.41%) fell 5.83%. With all the attention focused on the Dow's new stocks, a few analysts took a deeper look at Goldman this past week and didn't have good things to say. A Guggenheim analyst, thinking that future interest-rate changes might negatively affect Goldman's income from the capital markets, cut the firm's rating on the stock from "buy" to "neutral" and slapped on a $183 price target. Meanwhile, an analyst at Sanford C. Bernstein cut his third-quarter EPS estimate on Goldman for fear that trading revenues could soon decline. Maybe next week Goldman will make friends with the cool kids at the new school.  

The runner-up for the Dow's top loser this week was Cisco (CSCO 2.23%), which fell 4.81%. CEO John Chambers didn't do the stock price any favors this past week, when he appeared on CNBC's Closing Bell. Last month, the company gave weaker-than-expected guidance for the fourth quarter, but on the program, Chambers said European demand is recovering while emerging markets are mixed, and that the U.S. is a growth engine. Investors already knew things weren't great, but Chambers was putting lipstick on a pig by calling the U.S. -- which saw 2.5% GDP growth in the second quarter -- a growth engine, while the company itself only expects 3%-5% revenue growth in its fiscal Q1 2014. As investors, we want straightforward answers from management about the health and future of a company, and when we get muddled responses, the share price is likely to take a bigger hit than it truly deserves.

And in third place, after losing 3.32%, was Intel (INTC 0.33%). The company's board of directors announced this week that for the sixth straight quarter, the dividend will remain at $0.222 per share. The company's previous $0.21 payout lasted only four quarters. The last time Intel didn't change its payout over six periods was in 2008-2009, in the midst of the financial crisis. Dividend increases tend to signal that management thinks future free cash flows will cover the distribution amount while leaving the company the funds it needs to operate and continue to grow. But when the payout doesn't move, investors start to worry that the business may begin struggling or, at least, is no longer growing revenues and free cash flow.  

The other Dow losers this week:

(For more information on why shares of the other losers fell lower this past week, click on the links.)