Wild week ends with more stock volatility

A rout in technology shares deepened Friday, pushing the S&P 500 Index into corrective territory with the Nasdaq Composite Index, as one of the most tumultuous weeks in equity markets this year draws to a close. Treasuries and gold rose as investors sought refuge.

The S&P 500 had cut a loss that approached 3 percent by more than half before pushing lower again, and remains on track for the worst month in eight years. The tech-heavy Nasdaq indexes bore the brunt of selling after Amazon.com and Alphabet sank on disappointing results. The Chicago Board Options Exchange Volatility Index shows price swings are the greatest since February. Investors got a brief reprise after a report showed the U.S. economy expanded at a high-than-forecast 3.5 percent pace last quarter.

“It’s a very treacherous environment because you see these big up days and then they get their heads handed to them,” said Donald Selkin, chief market strategist at Newbridge Securities. “There’s no consistency. It’s vicious, it’s nerve wracking. There’s no consistency.”

The rout that had largely been contained to equities spilled into other assets Friday. Gold spiked toward the highest since July and the rally in Treasuries pushed the two-year note yield down 10 basis points this week. Yields on benchmark 10-year notes have slumped 11 basis points, the biggest weekly decline since May.

In Europe, the Stoxx Europe 600 Index continued its retreat, heading for the biggest monthly drop in three years. Asian shares sank deeper into a bear market earlier. Core European bonds gained as the risk-off mood spread.

Markets remain on edge after more than $6.7 trillion was lost from global equities’ value since late September, as lofty expectations for earnings were tested amid heightened trade tensions and tightening financial conditions.

Meanwhile, West Texas oil briefly dipped back below $67 a barrel and copper headed to close the week lower. The offshore yuan extended this week’s slide to trade at the weakest since January 2017, while the yen pushed higher.