NEW YORK (TheStreet) -- Falling oil prices stole the market's attention again on Tuesday after more signs of a slowdown in China spooked commodity traders. 

So stocks had an unpredictable day as benchmark indexes struggled to hold gains through the morning, before slumping in the afternoon session. 

The S&P 500 was down 0.68%, and the Nasdaq declined 0.87%. The Dow Jones Industrial Average slid 0.29%, snapping a seven-session winning streak. 

SanDisk (SNDK) spiked on reports the storage device developer is exploring a potential sale, according to Bloomberg. Shares were up more than 13% in extended trading. The company has yet to comment on the report. 

JPMorgan (JPM - Get Report) reported a 22% increase in quarterly profit as cost-cutting efforts translated to the bottom line. However, shares dropped nearly 1% in after-market trading as net income of $1.32 a share missed estimates by a nickel. Third-quarter revenue fell 6.4% to $23.54 billion. 

Intel (INTC - Get Report) edged higher after beating analysts' estimates on its top- and bottom-line. The hardware company earned 64 cents a share in its third quarter, 5 cents above expectations, while revenue of $14.47 billion surpassed forecasts by $250 million. 

Dollar General (DG - Get Report) shares were on watch after the discount chain reported plans to cut 255 jobs as part of a restructuring. The company expects to take a pretax cash charge of $7 million in its third quarter. 

Chinese imports and exports slumped in September, the second straight month of negative growth. Imports fell 20.4% year over year, a steeper decline than an expected 15% drop. Exports slid 3.7% compared to an expected 6.3% gain. The steep decline in imports created a trade surplus of $60.34 billion.

Fears over China, the world's second-largest consumer of oil, put a damper on crude oil prices. West Texas Intermediate closed 0.9% lower at $46.66 a barrel after a 5% decline a day earlier. The commodity had surged around 8% over the previous week on signs of slowing domestic production.

"China is one of the biggest consumers of commodities and a drop in imports would directly affect the demand," Daniel Ang, investment analyst at Phillip Capital, wrote in a report. "This worry should cause some reservations to further price increases and thus, suggest some capped upside."

The international oil market will likely remain oversupplied well into 2016, according to a report from the International Energy Agency. The IEA reduced forecasts for global demand growth next year by around 200,000 barrels a day compared to a previous estimate. The watchdog expects consumption to grow by 1.2 million barrels a day compared to 1.8 million this year.

The report conflicts with an outlook from the Organization of the Petroleum Exporting Countries out Monday which predicted global markets would begin to rebalance next year as U.S. production slows. 

Smaller oilers were among the worst performers in the energy sector on Tuesday. Valero Energy (VLO - Get Report) , Canadian Natural Resource (CNQ - Get Report) , Baker Hughes (BHI) , and Pioneer Natural Resources (PXD - Get Report) ended the day in the red. The Energy Select Sector SPDR ETF (XLE - Get Report) slid 1%. 

Twitter (TWTR - Get Report) jumped 1.1% after announcing it will cut 336 jobs, or around 8% of its work force, as part of a restructuring. The social network expects to incur between $10 million and $20 million in cash expenditures tied to severance costs.

Fortress Investment Group (FIG) spiked more than 7% after announcing it will close its Fortress Macro Funds and managed separate accounts. The investment firm said all capital will be returned to investors by the end of the year. Shares had been halted briefly prior to the announcement.

Anheuser-Busch InBev (BUD) and SABMiller (SBMRY) agreed to a deal that would combine the two largest beer companies in the world. Anheuser-Busch has agreed to purchase SABMiller for 68 billion pounds ($104 billion) or 44 pounds a share. SABMiller had previously rejected an offer to purchase the company for 42 pounds a share. The deal creates the world's largest beer company with nine of the world's top 20 beers under the one roof.

Johnson & Johnson (JNJ - Get Report) kicked off a busy earnings week after reporting a mixed third quarter. The drugmaker earned $1.49 a share, 4 cents above estimates, while sales fell 7.4% to $17.1 billion. Johnson & Johnson also announced plans to buy back up to $10 billion of common stock.

Agricultural chemicals company FMC Corp. (FMC - Get Report) joined rivals Monsanto (MON) and DuPont (DD - Get Report) in forecasting lower full-year earnings in the face of weakened industry demand and a decline in the Brazilian real. The company lowered profit forecasts to $2.35 to $2.45 a share, below previous estimates of $3 to $3.30 a share. FMC also announced it will cut as many as 850 jobs, or around 12% of its work force.

SAP (SAP - Get Report) shares jumped more than 5% after reporting a 19% increase in operating profit during the third quarter and a 17% increase in adjusted revenue. The software company said the stronger-than-expected results were largely thanks to double-digit growth in cloud software sales.