Stocks extended losses by mid-afternoon Tuesday as a sudden decline in IBM (IBM - Get Report) shares pressured the Dow Jones Industrial Average

The S&P 500 was down 0.31%, the Dow fell 0.29%, and the Nasdaq slid 0.17%.

IBM fell more than 3% on news the Securities Exchange Commission was conducting an investigation into revenue recognition in some of its transactions in the U.S., U.K. and Ireland. The hardware giant said it will fully cooperate with the agency's investigation. 

"IBM has a rigorous and disciplined process for the preparation of its financial statements and the reporting of revenue," said Ian Colley, vice president of IBM Communications, in a statement. "We are confident that the results and information we report have been appropriate and consistent."

Crude oil prices extended losses on Tuesday after closing at their lowest level since late August a day earlier. Worse-than-expected data including a drop in consumer confidence and weak durable goods added to already-present fears over global oversupply and soft demand. West Texas Intermediate crude closed down 1.8% to $43.20 a barrel.

Energy stocks were the worst performers on markets. Exxon Mobil (XOM - Get Report) , Chevron (CVX - Get Report) , ConocoPhillips (COP - Get Report) , Royal Dutch Shell (RDS.A - Get Report) , Total (TOT - Get Report) , and PetroChina (PTR - Get Report) moved lower, while the Energy Select Sector SPDR ETF (XLE - Get Report) fell 1.6%.

Consumer confidence weakened in October after reaching its second-highest level of the year a month earlier. Optimism over present conditions in the economy declined, particularly in the labor market. The Conference Board reported a drop to 97.6 in October, down from a downwardly revised reading of 102.6 in September. Economists had expected the measure to drop to 102.1.

"It seems as though the slowing in payroll employment gains has begun to hit consumer confidence a bit and offsetting the pop in equities and lower energy prices in the month," said BNP Paribas analyst Derek Lindsey in a note. "Still, the level of optimism remains solidly above that we saw this time last year."

Durable goods orders in September fell 1.2%, the second consecutive monthly drop, as the stronger U.S. dollar, weaker global economy and suffering energy sector reduced demand for capital goods. The drop was smaller than an expected 2.3% decline. The reading is the last piece of data to be digested before the first third-quarter growth estimate is released on Thursday. Economists expect third-quarter GDP to drop to 1.6% after a final second-quarter reading of 3.9%.

Rite Aid (RAD - Get Report) rocketed more than 30% higher on Wall Street Journal reports Walgreens Boots Alliance (WBA - Get Report) is considering an acquisition. Any deal between the two would combine two of the largest U.S. drugstore chains. 

The Federal Reserve began a two-day meeting on Tuesday. While the central bank isn't expected to raise interest rates at the October meeting, Wall Street will be listening for clues about the possibility of a rate hike when the Fed meets again in December.

"Expectations are for no action but the market will look for clues on the Fed's perception of both domestic and international recovery prospects," Peter Hug, global trading director at Kitco Metals, wrote in a note. "The Fed is likely not to move in December and risk being labelled the Grinch, should a hike hit the equity markets and a greater possibility is the Fed offering a firm statement that 2016 is the more likely launch point."

Comcast (CMCSA - Get Report) shares were 1.1% lower after reporting an in-line third quarter. The cable company earned 80 cents a share over the quarter, while revenue jumped 11% to $18.67 billion. CEO Brian Roberts called the results a "great quarter" after the box-office success of NBCUniversal's Minions and on growth in its high-speed Internet business.

DuPont (DD - Get Report) climbed 2% despite a sharp decline in profits. The chemicals company earned 13 cents a share in its third quarter, down from 54 cents a year earlier, as a stronger dollar and weaker demand in emerging markets took their toll. Results were better than the 10 cents analysts had expected.

Coach (COH) jumped 5% after maintaining full-year sales guidance and besting quarterly profit estimates. The luxury handbag retailer earned 41 cents a share in its fiscal first quarter, a penny above forecasts. Quarterly net sales climbed 3% on a constant-currency basis.

UPS (UPS - Get Report) fell 3% as sales came in weaker than expected after international package deliveries fell 7%. The delivery company expects full-year earnings no higher than $5.30 a share, coming in on the soft side compared to average estimates of $5.28 a share.

Ford (F - Get Report) dropped more than 2% after quarterly net income missed estimates. The automaker reported earnings of 45 cents a share, 2 cents below expectations. Revenue of $38.1 billion beat forecasts by $3 billion.

Alibaba (BABA - Get Report) shares surged 10% after a better-than-expected quarter. The Chinese e-commerce company reported a 28% increase in gross merchandise volume to $112 billion, with revenue through its mobile platform up 183%. The number of mobile monthly users jumped 59% to 346 million.

Pfizer (PFE - Get Report) posted adjusted third-quarter earnings of 60 cents a share, which was above analysts' estimates. The drug giant raised its outlook for full-year profit and revenue. The stock rose 2.5%.

Rival drugmaker Bristol-Myers Squibb (BMY - Get Report) climbed more than 2% after beating top- and bottom-line estimates. The company earned 39 cents a share, 4 cents above forecasts, while revenue climbed 4% on sales of its arthritis and stroke drugs.