The failure of lawmakers to resolve the debt crisis over the weekend sent the markets tumbling to a lower open with the Dow dropping 79 points to 15,158. Nasdaq lost 14 points to 3777.

On the upside

The Food and Drug Administration approved Antares Pharma's (Nasdaq: ATRS) rheumatoid arthritis treatment OTREXUP.

Wedbush analyst Betsy Van Hees upgraded Advanced Micro Devices (NYSE: AMD) from a Neutral rating to an Outperform rating.

Wells Fargo upgraded Liberty Interactive (Nasdaq: LINTA) from a Market Perform rating to an Outperform rating.

On the downside

Coronado Biosciences (Nasdaq: CNDO) reported disappointing results from a Phase 2 TRUST-1 clinical trial for its Crohn's disease treatment TSO.

Deutsche Bank analyst Ross Sandler downgraded Expedia (Nasdaq: EXPE) from a Buy rating to a Hold rating and cut his price target from $66 to $51.

Oppenheimer lowered its price target on Amarin (Nasdaq: AMRN).

In the broad market, declining issues outpaced advancers by a margin of more than 4 to 1 on the NYSE and by nearly 3 to 1 on Nasdaq. The broader S&P 500 lost 9 points to 1694.