A $2 trillion boost from Congress is a good start. Expect more.

WASHINGTON (CNN) — Here’s a much-needed dose of good news for investors: Lawmakers in Washington have reached an agreement on a sweeping $2 trillion economic stimulus package that will help support companies and workers harmed by the coronavirus pandemic.

Anticipation of such a deal sent US stocks soaring on Tuesday, with the S&P 500 rising 9.4% — its tenth best day ever and strongest performance since 2008, according to Bespoke Investment Group.

But, as has become typical, stocks are struggling to hold onto their gains. European shares powered higher in early trading but have since pulled back.

Goldman Sachs told clients Tuesday that the “swift and large” global policy response could help steady markets — but commitments may need to get even bigger before that happens.

The investment bank said that three other components are also needed to stabilize markets: A sign the infection rate is peaking, an indication the economic downturn may be slowing and cheap valuations. With the exception of valuations, we’re not quite there yet.

In the meantime, major risks remain — especially on the unemployment front. If joblessness shoots up, Goldman Sachs warns that companies could wind up short on cash as demand falters even more, raising the chances that the recession “becomes more entrenched.”

Andrew Hunter, senior US economist at Capital Economics, thinks the $2 trillion stimulus plan will help limit corporate bankruptcies and thus job losses.

But the research firm still sees the unemployment rate in the country soaring above 10%, and the economy contracting at an annual rate of as much as 40% between April and June.

Capital Economics also thinks that the US government will need to add to its $2 trillion efforts down the line.

“There is no reason to believe that Congress will now sit on its hands,” Hunter told clients. “Fiscal stimulus measures could easily be ramped up even further over the next couple of months as the economic damage becomes clear.”

Nike earnings show a way forward
How can retailers navigate the coronavirus pandemic as stores around the world shut down? Investors think Nike could offer some clues.

The retailer’s revenue between December and February beat investors’ expectations despite a heavy reliance on China, pushing shares up 12% in premarket trading.

Driving the enthusiasm: Nike said that sales in Greater China fell 4% last quarter, after 22 consecutive quarters of double-digit growth. But online sales in the region increased by more than 30%, helping to compensate for the fact that three quarters of its locations were temporarily closed. The company said that nearly 80% have now reopened.

“We’re seeing the other side of the crisis in China,” CEO John Donahoe told analysts Tuesday.

UBS analyst Jay Sole said the strength of online sales eases some concerns about cash flow and will put Nike in a better place than expected when the crisis ends. But the company still faces tough months ahead. All stores outside Greater China, Japan and Korea have been closed since March 16.

See here: Retailers will soon need to start offering huge discounts on spring clothing in an attempt to clear out inventory, my CNN Business colleague Nathaniel Meyersohn reports.

“People aren’t interested in buying anything but the things they need to stay alive,” said Mark Cohen, director of retail studies at Columbia Business School.

Why gig economy workers need help now
Millions of gig economy workers across the world are facing an impossible choice as a result of the coronavirus pandemic: break lockdown rules, or stay home and earn nothing, my CNN Business colleague Hanna Ziady reports.

The dilemma was illustrated Tuesday by images of packed subway cars in London less than 12 hours after Prime Minister Boris Johnson announced stricter social distancing measures as part of a nationwide lockdown.

The new coronavirus restrictions mean people are only allowed to leave their homes for medical reasons, to grocery shop or exercise once a day, and to travel to and from work when absolutely necessary.

But lockdowns won’t be effective if individuals who cannot work from home continue reporting to job sites because not doing so would deprive them of income. “Many of those traveling to work today … work in the gig economy or are freelancers,” London Mayor Sadiq Khan said Tuesday on Twitter. “A proper package of support for these workers would alleviate this situation.”