President Donald Trump's 25% tariffs on imports of steel and aluminium into the US took effect on Wednesday, in the latest escalation of trade tensions.
The European Union quickly responded by saying that it would impose counter tariffs on €26bn (£21.92bn) worth of US goods.
Trump announced the global tariffs on metal imports in mid-February, among other levies on Mexico, Canada and China that were unveiled last month. On Tuesday, Trump also rolled back on plans to impose 50% tariffs on imports of steel and aluminium, just hours after making the threat.
Shares in United States Steel (X) rose 5.5% on Tuesday but were hovering just above the flatline in pre-market trading on Wednesday.
Concerns have been growing that tariffs could stoke already stubborn inflation and drag on slower economic growth. These fears have sparked a sell-off in markets over the past couple of days, after Trump declined to rule out the possibility that the US economy could dip into a recession this year.
Richard Hunter, head of markets at Interactive Investor, said: "Trade policy continues to top the list of investor concerns. One of the many reasons why markets dislike uncertainty is the inability to foresee the immediate future given the wider economic backdrop, something which is currently nigh on impossible given the fluctuating messages coming from the White House on an almost daily basis."
"It appears that the tariff story has further to run, with more changes along the way, which in turn will keep volatility higher until at least some of the economic dust settles."
Server maker Super Micro Computer (SMCI) was the top riser in the S&P 500 (^GSPC) on Tuesday, as artificial intelligence (AI) stocks rebounded from Monday's sell-off.
Super Micro shares started to climb on Monday, despite wider volatility, after Rosenblatt Securities analyst Kevin Cassidy reinitiated coverage of the stock with a "buy" rating, according to a Barron's report.
Shares in Intel (INTC) surged 8% in pre-market trading on Wednesday, following a report that TSMC (2330.TW, TSM) had pitched to other chipmakers taking stakes as part of a joint venture to operate the company's factories.
Reuters reported that TSMC (2330.TW, TSM) had pitched the joint venture to Nvidia (NVDA), Advanced Micro Devices (AMD) and Broadcom (AVGO), that would see the Taiwanese chipmaker run the operations of its foundry division. However, sources reportedly said TSMC (2330.TW, TSM) would not own more than 50% of the business.
Intel (INTC), TSMC (2330.TW, TSM), Nvidia (NVDA), AMD (AMD) and Broadcom (AVGO) had not responded to Yahoo Finance UK's request for comment at the time of writing.
In the third quarter of last year, Intel (INTC) announced its intent to establish the foundry business as an independent subsidiary.
The company's struggles have made it an acquisition target, with reports that it has attracted interest from TSMC (2330.TW, TSM) and Broadcom (AVGO), among others.
Shares in Zara-owner Inditex slumped 7.5% on Wednesday morning, after the clothing company's latest results showed a slower start to sales in the first quarter.
In its full-year results released on Wednesday, Inditex said sales were up 4% between 1 February and 10 March, compared with 11% for the same period last year.
For the year ended on 31 January, Inditex reported a 7.5% increase in sales to €38.6bn, while profit before tax was up 10% to €7.6bn.
Russ Mould, investment director at AJ Bell (AJB.L), said: "A slowdown in Inditex’s sales growth is reason to worry as it implies consumers aren’t feeling as confident with opening their wallets. The uncertain backdrop is creating havoc for companies across multiple industries and retail is near the top of the list.
"Inditex is one of the few retailers that act as economic bellwethers. The owner of much-loved brands Zara, Bershka and Massimo Dutti, the company has a reputation for good quality clothes at fair prices. They might not be the cheapest, but you know they’ll last a while and look good."
"With so much negativity in the news, it’s no wonder individuals are starting to wonder if they really need that new top or dress," Mould added. "They might feel it is better to hold on to that money just in case something nasty comes around the corner."
Shares in Porsche fell nearly 5% on Wednesday morning, after the luxury car brand reported a 23% fall in operating profit in 2024 to €5.64bn.
The German carmaker said earnings in 2024 were mainly impacted by a "challenging economic environment and the comprehensive renewal of the product portfolio. The tense market situation in China, the delayed global ramp-up of electromobility and disruptions in the supplier network had an impact on earnings and return on sales."
Looking ahead, Porsche said it expected to generate an operating return on sales of 10% to 12% in 2025, which is below the figure for 2024 financial year.
AJ Bell's Mould said: "The whole industry was already in a difficult place as it dealt with a mismatch between regulation around the transition to electric vehicles and uneven demand for EVs among consumers, as well as mounting competition from China and weak consumer sentiment."
"At Porsche, this has been compounded by supply chain issues and delays in the roll-out of new models. Now tariffs have been added to the mix it looks even harder for Porsche to arrive at its goal of a 20% margin."
Other companies in the news on Wednesday 12 March:
