Weakness in some of the biggest technology companies sent U.S. stocks tumbling Monday as pessimism about escalating trade tensions between the Trump Administration and China added to concerns about potential new regulations coming for the industry. The dollar steadied and Treasuries crept higher for a fifth straight session.

All major American benchmarks were down more than 1.5 per cent. Software developers and semiconductor manufacturers were the worst performing groups in the S&P 500 Index. The Nasdaq 100 Index plunged more than 3 per cent to the lowest since April on renewed concern that trade fights will tamp down global demand and disrupt supply chains for the major technology companies that have carried the bull market for almost 10 years. In addition, the biggest drop in homebuilder sentiment in more than four years hammered the housing sector.

In Canada, the S&P/TSX Composite closed down 84.49 points at 15,071.01.

“The easiest way to stop the selloff would be for Trump and [Chinese President] Xi to reach some kind of agreement, even if it’s just no new tariffs and/or keeping the rate at 10 per cent through Jan. 1,” said Max Gokhman, head of asset allocation for Pacific Life Fund Advisors. “The U.S. equity market is starting to price in the supply chain disruption, which is doubly painful because of stretched margins.”

Here are some of the key moves:

Apple Inc. sank following reports that it had cut production orders for the three iPhone models it unveiled in September. Facebook Inc. dropped as its public image remains under pressure. Snap Inc. and Twitter Inc. tumbled too as social media shares were broadly punished. Nvidia Corp.’s two-day plunge reached nearly 28 per cent after its disappointing earnings, as chipmaker shares remained in a tailspin. Salesforce.com fell 9 per cent, the most since February 2016. The SPDR S&P Homebuilders ETF reversed an earlier gain to trade lower following the housing sentiment report.

“You’re seeing weakness in semiconductors because of Nvidia’s weak earnings that were released last week,” said Ryan Nauman, market strategist at Informa Financial Intelligence. “Facebook is having some more issues with potentially covering up the Russia hack in the 2016 election. Apple, they’re getting downgraded based on demand. A lot of companies and analysts are concerned that the demand for the iPhone has decreased. The trade concern isn’t helping Apple much either with the supply chain.”

Investors are reassessing markets after several weeks of volatility spurred by fears of trade conflicts. The Asia-Pacific Economic Cooperation failed to agree on a joint statement for the first time in its history, and U.S. Vice President Mike Pence attacked China at a weekend summit, quashing optimism that relations would improve at Group-of-20 meetings starting next week. In addition, rising U.S. interest rates are pushing up financing costs and threatening global growth.

“Any margin for safety with global growth rates is gone,” said Tim Courtney, chief investment officer of Exencial Wealth Advisors in Oklahoma City. “Now we’re going into a period of slow growth. We’re in no-man’s land -- sitting, stuck in a slow growing, slow inflationary environment.”

In Europe, the Stoxx 600 Index fell following a plunge in Renault SA on misconduct allegations against the carmaker’s leader, Carlos Ghosn. European bonds mostly edged lower. The pound fluctuated as U.K. Prime Minister Theresa May appealed to business leaders to help deliver her Brexit deal, and Gibraltar emerged as a fresh sticking point.

Elsewhere, the Australian and New Zealand currencies slipped after Pence’s remarks. Bitcoin fell below US$5,000 for the first time since October 2017. Crude closed in on US$57 a barrel as energy stocks rebounded.

These are the main moves in markets:

Stocks

The S&P 500 sank 1.7 per cent to 2,690.73, while the Nasdaq 100 plunged 3.3 per cent. The Stoxx Europe 600 Index dipped 0.3 per cent. The  U.K.’s FTSE 100 Index gained 0.1 per cent. The MSCI All-Country World Index dropped 1 per cent.

Currencies

The Bloomberg Dollar Spot Index was little changed. The euro climbed 0.3 per cent to US$1.1451. The British pound added 0.1 per cent to US$1.285. The Japanese yen rose 0.3 per cent to 112.54 per dollar.

Bonds

The yield on 10-year Treasuries declined 1 basis point to 3.0537 per cent. Britain’s 10-year yield decreased three basis point to 1.378 per cent. Germany’s 10-year yield jumped one basis point to 0.373 per cent.

Commodities

The Bloomberg Commodity Index gained 1.1 per cent. West Texas Intermediate crude climbed 0.5 per cent to US$56.76 a barrel. Natural gas rose 7 per cent to US$4.583 per mmbtu. Gold was little changed at US$1,223.43.