Concerns over the epidemic triggered a surprising drop in US consumer confidence, causing the US and European stock markets to make tiny gains on Friday following days of record highs.

On Wall Street, the Dow and S&P 500 eked out a fourth consecutive record close and tiny weekly advances in light summer trading.

To round out the week, European markets moved higher, with Frankfurt’s DAX 30 briefly crossing the 16,000-point mark for the first time and Paris briefly reaching a 21-year high.

US stocks opened higher, but fell after the University of Michigan reported that its consumer mood index had dropped to its lowest level in a decade due to the proliferation of the Delta form of Covid-19.

According to the survey’s head economist, Richard Curtin, “there is little doubt that the pandemic’s comeback owing to the Delta variety has been met with a mixture of reason and emotion” by consumers.

The measure plunged 13.5 percent to 70.2, one of the greatest drops ever recorded, owing to “dashed hopes that the pandemic would soon stop” and the realistic conclusion that the economy would suffer, he added.

Earnings season is coming to an end, but good quarterly results have helped to lift stocks on both sides of the Atlantic.

“Small and steady advances that have seen European equities push into record territory have been a typical aspect of the markets recently,” said Craig Erlam, senior market analyst at OANDA.

The advances in Europe have also been driven by strong Covid vaccination campaigns, which have allowed countries to relax restrictions, according to Erlam.

However, growing Delta variant infections in the United States and mixed inflation statistics will focus attention next week on economic data, particularly retail sales, for a better sense on the world’s largest economy’s outlook.

Further signs of inflationary pressures following mixed data this week would almost certainly force the Federal Reserve to begin winding down its enormous stimulus program sooner than expected.

Fed Chairman Jerome Powell is scheduled to speak later this month at the annual central banking conference in Jackson Hole, Wyoming, which could be the occasion for the first promised early warning of a plan to slow the monthly pace of bond purchases.

The concern is that tapering, along with an increase in interest rates to combat inflation, will stymie the recovery.

“Global investors are weighing the ramifications of the Delta virus’s spread, the Fed’s potential tapering, and China’s crackdown,” Federated Hermes’ Geir Lode said.

Stock markets in Asia closed lower after a mostly favorable week, as the Chinese government tightens its control on the world’s second-largest economy.

The International Energy Agency warned in a research on Thursday that the Delta mutation will affect demand, which spurred the recent sell-off in crude prices.