As the likelihood of additional federal stimulus fades, U.S. stock investors are returning their focus to the coronavirus pandemic and not liking what they see.

High-frequency data that tracks economic activity shows a slowdown in the recovery from the height of the lockdowns, with Americans again cutting back on flights and going out to eat less often. Public-transit use also remains low, while jobless claims are stubbornly elevated. Meanwhile, the prospects for a vaccine in the next few months have also waned just as the latest data shows an uptick in cases.

That again sent a jolt through financial markets. Equities eked out gains after a volatile session, with tech shares bouncing back from Wednesday’s 3% rout, but the S&P 500 remains on pace for their longest weekly losing streak since August 2019.

For all the things buffeting markets right now, none is more important than the race to find an inoculation to the virus. While Federal Reserve largesse and $3 trillion of federal stimulus helped fuel a torrid five-month rally that began in March, their limitations have become clear as the virus continues to spread.

“We have been trading the likelihood of a vaccine and you can see that in the data,” David Kostin, Goldman Sachs Group Inc.’s chief U.S. equity strategist, said in an interview with Bloomberg TV and Radio.