All three of the big share indexes in the US are now trading down more than 5%. That's huge, especially after the big declines we saw yesterday.

The sell-off started yesterday when firms such as Apple and Nike, which rely heavily on suppliers in Asia, were hammered. But today, the falls are moving into sectors that would typically not face direct impact of tariffs, such as healthcare and utilities.

I just got off the phone with Mike Dickson, head of research and quantitative strategies at Horizon Investments in the US.

"Candidly the mood is pretty sour and it should be," he said, warning that it will take weeks to understand the impact of Trump's tariffs.

He added that there were few parts of the market that had escaped unscathed. "It looks like people are just selling straight to cash. There's a lot of uncertainty."

Simeon Siegel is managing director at BMO Capital Markets. He tracks companies such as Nike, which makes the vast majority of its shoes and clothing in countries hit hard by Trump's tariffs.

The firm's shares tumbled yesterday, reflecting worries about how the company will handle the sudden jump in costs due to the tariffs, which are set to go into effect on 9 April.

They are clawing back some of that ground today, buoyed by hopes that Trump's comments on Vietnam signal willingness to negotiate a deal.

Other retailers, such as Gap, have seen similar gains.

“Most companies are looking at last night’s announcement as still far from the final conclusion,” Siegel says.

“Despite the glossy, fancy, shiny table, I don’t think that many people believe that those numbers are etched in stone just yet. Companies are still trying to figure out what this means.”

(Source: BBC)