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.

For a fifth straight day, the S&P 500 Index (SNPINDEX:^GSPC) fell, losing 4 points, or 0.3%, to end at 1,692. The recent pullback has been driven by political discord on Capitol Hill; an Oct. 1 deadline looms as our nation's top brass have until that date to officially raise the debt ceiling. If partisan politics get in the way of reaching an agreement, the United States would default, and stock markets would probably not take kindly to that. This isn't the most likely outcome, but as time drags on and no decision is reached, expect stocks to continue losing ground.

No stock should lose as much ground as J.C. Penney (OTC:JCPN.Q) did today: Shares in the department store were absolutely slaughtered today, losing 15%. The stock took a dive Wednesday after Goldman Sachs downgraded J.C. Penney, even though the investment bank is also working with J.C. Penney to help it raise money. The current dynamic raises more questions about Goldman's ethics than J.C. Penney's business. 

Carnival (NYSE:CCL) plummeted for a second straight day, losing 5.3% after a massive 7.7% drop yesterday. The cruise-line operator has been suffering the consequences from several nightmarish events on its ships: The Costa Concordia wrecked last year, killing passengers as its captain escaped, and a separate Carnival-operated ship went on to lose air conditioning and plumbing capabilities for days on end, leaving customers stranded. On top of that, its quarterly report yesterday portrayed a bleak future for the company.

Lastly, business software and services company Iron Mountain (NYSE:IRM) lost 3.1% Wednesday, even as it began construction on its very first regional data center in Massachusetts. Although the market may not be crazy about Iron Mountain dropping some big bills on tech at the moment, it's a forward-looking move from the storage company. On Oct. 28, investors will know how Iron Mountain's most recent quarter played out and can glean a better idea about what to expect from the future.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.