Stocks up slightly in first day of trading after huge October

Stocks opened slightly higher on Wall Street as the market came off its biggest monthly gain in four years.

Monday’s early gains followed an incredible October, during which the Standard & Poor’s 500 stock index rose 8%, its best month since October 2011.

Health care stocks were among the early winners Monday. Drug giant Pfizer rose 1%, the biggest gain in the Dow Jones industrial average.

Visa lagged the market. The payments processing company slumped 3% after announcing a deal to combine with its European counterpart.

Chipotle Mexican Grill fell 4%. The company shuttered its restaurants in Portland and Seattle after an outbreak of E. coli.

The Dow average gained 57 points, or 0.3%, to 17,719 as of 6:35 a.m. Pacific time.

The S&P 500 index was up seven points, or 0.3%, to 2,086.

The Nasdaq composite climbed 15 points, or 0.3%, to 5,070.