Updated from 11:46 a.m.

Stocks slid deeper into the red on Wednesday afternoon, as the Dow Jones Industrial Average fell and put the 20,000 milestone farther out of reach and all S&P 500 sectors slumped. 

The Dow dropped 0.51%, while the S&P 500 fell 0.79% and the Nasdaq declined 0.91%.

The dip helped prolong days of speculation about when the Dow might reach 20,000, a historic high. The index of 30 blue-chip stocks stretched to within 19 points of the milestone on Wednesday, before retreating. The Nasdaq slid from a record opening of 5,499.

"With the runup we have had in equities over the past six or eight weeks, a lot of people, including us, would not be surprised to see a modest pullback in equities in the neighborhood of 3% to 5% at most," David Schiegoleit, U.S. Bank managing director of investments, said in a phone interview. "It's been a very hard and quick runup since the election and letting off a little bit of steam really would not surprise us." 

All 11 S&P 500 sectors were lower, with financials, materials and real estate as the biggest losers. Travelers  (TRV) - Get Reportled the Dow, up 0.07% as the only company in positive territory. 

Schiegoleit also highlighted that markets are trading with very light volume today, "so any modest down pressure or for that matter upward pressure get a little bit magnified on days like this, simply because of the low volume."

Crude oil prices are in positive territory for the fourth consecutive day as investors anticipated lower global oil production based on an agreement by the Organization of Petroleum Exporting Countries. West Texas Intermediate crude oil climbed less than 1% to $54.06 a barrel on Wednesday. Brent crude, the global benchmark, traded at $56.45, also up less than 1%.

On the economic calendar, the November pending home sales index declined 2.5% from the prior month, according to the National Association of Realtors. The index fell from 110 to 107.3 as prospective home buyers grapple with rising mortgage interest rates following Donald Trump's election.

U.S. prosecutors charged three Chinese citizens with hacking into law firms to obtain confidential information on deals involving Intermune (ITMN) and Roche; Intel (INTC) - Get Report and Altera; and Pitney Bowes (PBI) - Get Report and BorderFree. The hackers were said to have made $4 million in in profits on trades related to about five companies.

Qualcomm (QCOM) - Get Report was fined 1.03 trillion won ($853 million) by the Korean Fair Trade Commission. The watchdog said that the digital communications technology company violated antitrust and competition laws with its patent license agreements. Qualcomm general counsel Don Rosenberg said the company disagreed with the findings and will appeal the decision. Shares of Qualcomm were down 2.1% to $65.87 in trading Wednesday.

Delta Air Lines (DAL) - Get Report said that it reached an agreement with Boeing to cancel 18 Boeing 787 Dreamliner aircraft orders. Based on list prices, the aircraft order was valued at $4 billion. Delta inherited the orders when it combined with Northwest Airlines in 2008.

"This business decision is consistent with Delta's fleet strategy to prudently address our wide body aircraft needs," said Greg May, Delta's senior vice president for supply chain management and fleet, in a statement.

Shares of Boeing (BA) - Get Report fell 0.9% and Delta's shares fell 1.5% following the news.

BP (BP) - Get Report ADRs were up 0.3% after the company announced the purchase of Australian retailer Woolworths in a deal worth 1.79 billion Australian dollars ($1.29 billion).

Galena Biopharma (GALE) , which specializes in hematology and oncology therapeutics, saw its shares soar more than 23.5% when the company announced it received regulatory confirmation after meeting with the U.S. Food and Drug Administration about its GALE-401 Phase III trial. The trial is expected to start before June of next year.

Toshiba (TOSYY) shares were in focus again after the company said Tuesday that its U.S. nuclear operation might record billions in losses. Shares of Toshiba fell 20%, and trading was halted in Toky

Kate Spade (KATE)  shares popped 21.8% after the Wall Street Journal reported that the apparel and accessories company is working with bankers on potentially selling the company.