Stocks fell deep into the red by mid-afternoon Tuesday as a selloff in gold prices pulled the materials sector into a spiral. 

The S&P 500 was down 0.55%, the Dow Jones Industrial Average fell 0.6%, and the Nasdaq slid 0.33%. 

Technical analyst Helene Meisler of Real Money, TheStreet's sister site for active traders, wrote that she's watching the Dow Jones Utility Average, which has tumbled for days to close Monday at 659.26. Meisler said a meaningful breakdown below 655 would be a bad sign for the broad market. Click here to check out her latest technical analysis.

Gold prices fell to their lowest level since the late-June Brexit vote as the U.S. dollar marched to a two-month high. Spot gold fell 3% on Tuesday afternoon to $1,269.70 an ounce, its worst one-day percentage decline since December 2013. Gold broke below the key support level of $1,300 an ounce, a level it has not breached since late June. 

A selloff in gold prices hit the materials sector hard. Gold companies Barrick Gold (ABX) , Newmont Mining (NEM) - Get Report , Goldcorp (GG) , Randgold Resources (GOLD) - Get Report , and Kingross Gold (KGC) - Get Report were all sharply lower. The SPDR Gold Trust ETF (GLD) - Get Report slid 3.2%.  

Stocks also pulled lower on reports the European Central Bank could begin winding down its quantitative easing program earlier than its targeted March 2017 end date. The central bank currently repurchases 80 billion euros (nearly $90 billion) a month, a program it could pare by 10 billion euros at a time, according to Bloomberg. ECB officials had previously expressed openness to extend the program beyond its March target, if need be. In a statement, the ECB said members had not discussed the possibility of ending sooner. 

The International Monetary Fund reiterated its forecast for weak global growth on Tuesday, pointing to softness in the United States' economy for overall weakness among advanced economies. The economic group cut its growth forecast for the U.S., the world's largest economy, to 1.6% from 2.2% in July.

The group also warned of a rise in populist figures, such as those involved in the Brexit push and the U.S. Republican presidential candidate Donald Trump, as slow growth fuels negative attitudes toward immigration and trade deals. The IMF anticipated global growth to climb 3.1% in 2016 and 3.4% in 2017, unchanged from its previous forecast.

"Taken as a whole, the world economy has moved sideways," IMF chief economist Maurice Obstfeld said in a statement. "Without determined policy action to support economic activity over the short and longer terms, sub-par growth at recent levels risks perpetuating itself."

Oil prices saw choppy trading on Tuesday as worries resurfaced over how effective a deal on oversupply among major oil producers would be. Reports surfaced that Libya and Iran have recently increased their output despite a deal reached last week among Organization of Petroleum Exporting Countries to cap production.

West Texas Intermediate crude closed 0.25% lower at $48.69 a barrel on Tuesday.

European markets closed higher for their sixth straight day after the pound fell to a 31-year low on worries over the Brexit execution. Worries over how and when the United Kingdom would exit the European Union have pressured the currency since the decision by voters in late June to leave the EU. A lower pound makes investment in U.K. businesses more attractive and U.K.-made products cheaper to international buyers. 

Apple (AAPL) - Get Report moved 1% higher on Tuesday, leading the Dow, after launching its Apple Pay service in Russia. The payment system is now available in 10 countries since first launching in 2014.

Apple is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells AAPL? Learn more now.

Sears (SHLD) spiked nearly 15% and was briefly halted on reports that bids for its Craftsman business were due by the end of the month. Potential bidders include Stanley Black & Decker (SWK) - Get Report , according to Bloomberg. 

Yahoo! (YHOO) was on watch on breaking news that it had built software to scan customers' emails at the request of U.S. intelligence. The company reportedly scanned its email service for specific information, according to Reuters

Pandora (P) spiked after Goldman Sachs added it to its conviction buy list and suggested a 34% upside to its current trading price. The firm pointed to opportunities in on-demand and premium subscriptions.

Darden Restaurants (DRI) - Get Report climbed 0.6% as strength at its Olive Garden franchise boosted earnings in its recent quarter. Same-store sales at the chain over the first quarter increased 2%. The company expects overall profit of $3.87 to $3.97 a share for the full year, up from its previous range that capped at $3.90 a share. (CRM) - Get Report agreed to acquire marketing and advertising analytics startup Krux late Monday afternoon. The cloud-computing company agreed to a cash-and-stock deal worth around $700 million. Krux and Salesforce previously had a partnership agreement.

Alphabet (GOOGL) - Get Report  unveiled two new smartphones, the Pixel and larger Pixel XL, at a Google event in San Francisco. The phones, the first designed purely in-house, also feature a personal assistant, similar to iPhone's Siri. The reveal of a smartphone was widely expected. 

Alphabet is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells GOOGL? Learn more now.

Kraft Heinz (KHC) - Get Report was added to JPMorgan's focus list on Tuesday. The firm said fundamentals are improving and that the stock also offers a 4% dividend yield.