Stocks that moved substantially or traded heavily Thursday:
Apple Inc., down $15.73 to $142.19
The tech giant said iPhone sales in China weakened over the holiday season and will fall far short of Wall Street forecasts.
Celgene Corp., up $13.79 to $80.43
Bristol-Myers Squibb agreed to buy the cancer drugmaker for $74 billion.
Intel Corp., down $2.59 to $44.49
Chipmakers and other technology companies slumped as investors feared Apple's comments were a bad sign for the industry.
3M Co., down $7.19 to $183.76
Shares in industrial companies fell following concerns about China's economy and a weak report on U.S. manufacturing.
Realty Income Corp., up 55 cents to $62.48
Share in real estate companies and other stocks that tend to do better in times of economic turmoil rose on Thursday.
Delta Air Lines Inc., down $4.48 to $45.61
Airline stocks dropped after Delta said its fourth-quarter revenue won't grow as much as it expected.
Freeport-McMoRan Inc., down 29 cents to $10.07
Copper prices slumped amid concern that slower economic growth will reduce demand for copper in construction.
Caterpillar Inc., down $4.87 to $121.51
A weak report Thursday on U.S. manufacturing also weighed on the market.