U.S. stocks fell more than 1% as political unrest in Hong Kong and Argentina fueled a rally in global bonds that continues to raise the specter of a looming recession. Gold surged.

The S&P 500 index slumped for a second day and now sits almost 5% below its all-time high as the rally in Treasuries sparked by last week’s escalating trade tensions picked up steam. Risk assets came under pressure after authorities closed Hong Kong’s airport and a Chinese official said the city was at a “critical juncture.” Argentina’s peso and equities sank after voters turned on the president in a primary vote. Corn futures plunged the most since 2013 as more of the grain was planted than analysts had estimated.

The weakness in stocks fed demand for haven assets, pushing the 10-year Treasury yield lower by 10 basis points and boosting the yen for a fourth day. China’s central bank fixing continued to signal its determination to manage an orderly depreciation. Italian bonds led gains in European debt after Fitch affirmed the country’s credit rating on Friday. The pound strengthened following three sessions of declines.

Monday’s sell-off in risk assets provided another reminder of the fragile mood across markets as it extended the tumultuous start to August. Gains for the safest government bonds show lingering caution by traders who’ve increased bets for central bank easing in recent weeks, as the U.S. and China escalate their trade war and a slew of global data point to slowing growth.

“It’s a day with very little news in terms of economic calendar and earnings and a week that’s going to have a lot of earnings that are very important. But it doesn’t look like there’s true sort of resiliency in the sell right now,” said JJ Kinahan, chief market strategist at TD Ameritrade. “The flight to bonds is really the more concerning element only because it flattens the yield curve.”