NEW YORK (TheStreet) -- The Federal Reserve helped fuel a marketwide rally Thursday sending the Dow Jones Industrial Average to a 400-point gain after the central bank assured Wall Street it would be "patient" in determining when to raise rates.
The S&P 500 climbed 2.4% while the Nasdaq added 2.2%. The Dow rocketed 420 points, its largest advance since November 2011.
The Fed's pledge for patience in raising rates on Wednesday infused markets with new vigor on Thursday. Fed Chair Janet Yellen said the central bank would likely not increase rates for at least the next couple of meetings.
"It's really reconfirmation that they plan on starting to raise rates midway through next year... barring some big setback in either the labor market or the economy," said Chris Gaffney, senior market strategist at EverBank, in a call.
The markets and crude oil finally broke apart after weeks in lockstep as stocks soared even as commodity prices continued a steep decline. A bounce in crude oil prices had evaporated by the afternoon with fear resurfacing that the commodity had not yet found a bottom after weeks of steep losses. West Texas Intermediate crude slid 3.5% to $54.51 a barrel.
"It's too soon to call for a bottom but certainly investors with a longer-term strategy are finding a lot of good bargains at this point," said Sterne Agee chief economist Lindsey Piegza over the phone.
Saudi Arabia's oil minister, Ali al-Naimi, said Thursday that OPEC could not cut output and remedy the commodity slump alone lest it risk losing market share. The Saudi official said OPEC had called upon non-OPEC oil producers to restrict supply last month but that "those efforts were not successful."
Stocks held onto their session highs in the face of plunging oil after Yellen assured markets that there was no threat of financial spillover, said LPL Financial investment strategist John Canally. "Yellen was asked that directly and her answer was kind of soothing," said Canally. "She would err more on the side of caution if there was something going on. Clearly the Fed sees that there's not and I think that was a signal that maybe oil and the markets can decouple."
Commodity traders had hoped prices would stabilize as oil companies announced plans to limit investments in new production, moves that should pare global oversupply. Marathon Oil (MRO) and ConocoPhillips (COP) separately said they would slash 2015 capital expenditure by 20%, while Chevron (CVX) put plans to drill in the Canada's Beaufort Sea on hold indefinitely.
Tech giants such as Apple (AAPL) , Tesla (TSLA) and Facebook (FB) moved significantly higher, while the Technology SPDR ETF (XLK) surged 2.9%. Oracle (ORCL) was pulling enterprise software developers higher following a better-than-expected second quarter. Microsoft (MSFT) , Hewlett-Packard (HPQ) and Intel (INTC) jumped.
Sony (SNE) shares were up 3.7% after deciding to pull the release of The Interview, previously set to debut on Christmas Day. On Wednesday, major theater chains including AMC Entertainment (AMC) and Regal Entertainment (RGC) dropped plans to show the movie after threats from Sony hackers.
Rite Aid (RAD) climbed 11.9% as quarterly net income beat expectations and same-store sales in its third quarter spiked more than 5%.
Dunkin' Brands (DNKN) tumbled more than 6% as the company issued weaker-than-expected 2015 guidance, while Kraft Foods (KRFT) surged 6.3% after announcing it had appointed its Chairman John Cahill as its new CEO.
--Written by Keris Alison Lahiff in New York.