The sideshow in Washington continues as the government slowdown begins another week, and debt ceiling negotiations look like a non-starter. Both the Dow Jones Industrial Average (^DJI -1.64%) and the S&P 500 are fairly depressed this morning, and it seems a sure bet that a looming default on the U.S. debt is making markets nervous.

Happy faces
Some Dow companies are up today, notably AT&T (T -1.67%) and Verizon (VZ -1.00%) -- and they may have tech giant Apple to thank for it. The latter's spiking 5S and 5C iPhone sales have lifted its fortunes recently, and iPhone vendors AT&T and Verizon are sharing the spotlight, too, as both communications companies see increased sales for the popular gadgets.

Deals offered by big-box retailers Best Buy and Wal-Mart, which offer the iPhone 5C for half off the retail price -- and come with two-year contracts with AT&T, Sprint, or Verizon -- certainly can't be hurting, either.

Long faces
Many Dow components are listless today, with financials looking particularly wan. With no specific news about credit card issuers Visa (V -1.43%) and American Express (AXP -1.35%) on tap today, those companies could be suffering from a general fearfulness surrounding the debt ceiling crisis, and the effect that a lack of congressional action will have on the country's credit. Both credit card companies have experienced stellar share price growth over the past year, with Visa soaring by almost 34%, and American Express increasing by 25%.

JPMorgan Chase is also a laggard, reflecting some of the general malaise affecting markets so far today. Possibly causing some additional pain was a midmorning report on mortgage rates, in which analysts noted the huge jump in long-term interest rates since May. This has effectively cut the pool of refinance candidates in half, not good news for banks.