(CNN Money) — Investors are weighing the possibility that the U.S. government might shut down on October 1st. But even if a shutdown is avoided, the bigger concern is whether Congress will raise the debt ceiling before the drop-dead deadline of October 18. If that doesn't happen, the government risks defaulting on its debt. Another credit rating downgrade could be in the cards too.
The Dow Jones Industrial Average and S&P 500 closed slightly lower. Both indexes have now suffered four straight days of losses. The Nasdaq ended in positive territory ... but just barely.