U.S. stocks extended losses on Monday, dragged lower by a steep selloff in crude oil prices.

The S&P 500 fell 0.63%, the Dow Jones Industrial Average declined 0.61%, and the Nasdaq slid 0.59%.

Crude oil prices continued their slump after a meeting of the Organization of Petroleum Exporting Countries last week failed to produce output cuts. Global oil prices have been under pressure as demand slows while production remains near record highs. West Texas Intermediate crude fell 3.1% to $38.75 a barrel on Monday morning.

Energy stocks were sharply lower. Major oilers including Exxon Mobil (XOM - Get Report) , Chevron (CVX - Get Report) , PetroChina (PTR - Get Report) , Royal Dutch Shell (RDS.A - Get Report)  and BP (BP - Get Report) were more than 2% lower, while the Energy Select Sector SPDR ETF (XLE - Get Report) slumped 4%. 

With a December rate hike from the Federal Reserve already expected, investors were free to celebrate the latest sign of a tightening labor market, leading to a massive rally on U.S. markets. European markets followed suit Monday. Germany's DAX climbed 2.2%, the CAC 40 in France jumped 1.9%, and the FTSE 100 in London gained 0.46%.

Chipotle (CMG - Get Report) slumped 4% after the burrito chain warned that comparable sales would fall 8% to 11% in the fourth quarter as a result of an E. coli outbreak. Cases have recently been reported in three more states -- Illinois, Maryland and Pennsylvania. The outbreak has spread to nine states and affected 52 people.

Keurig Green Mountain (GMCR) shares surged more than 73% after the company agreed to be bought by JAB Holding in a deal worth $13.9 billion. Keurig shareholders will receive $92 in cash for each share they hold. The stock closed Friday at $51.70.

General Electric ( GE - Get Report) fell slightly after the company scrapped plans to sell its appliance business to Electrolux ( ELUXY) . The two companies were being sued by the Justice Department to stop the deal which would combine the second- and third-largest appliance manufacturers in the U.S.

Bluebird Bio (BLUE - Get Report) fell more than 30% after reporting mixed results from its gene therapy study into severe sickle cell patients. Two sickle cell patients infused with Bluebird's gene therapy have only shown small improvement after many months.

Pep Boys (PBY) jumped 7% on Monday after activist investor Carl Icahn disclosed a 12.12% stake in the company late Friday afternoon. Icahn also called for Pep Boys to be sold to Auto Plus, an auto chain owned by Icahn Enterprises.

Marvell Technology (MRVL - Get Report) fell more than 5% after reporting a preliminary third-quarter loss of 12 cents a share, well below 22 cents a share in profit a year earlier. The tech company said revenue fell 5%, dragged on my a 16% decline in storage sales. Marvell also said the Securities and Exchange Commission had been in contact regarding an accounting audit.