The UK’s financial regulators will investigate the London Metal Exchange’s handling of a week-long suspension of trading in nickel amid chaotic conditions at the start of Russia’s invasion of Ukraine. The LME suspended trading in nickel, a crucial material for electric car batteries, on 8 March after prices doubled over the course of a day to a record $100,000 (£76,200) a tonne. Trading in the metal reopened after a week, on 16 March. The exchange’s regulators, the Financial Conduct Authority (FCA) and the Bank of England (BoE) on Monday said in a joint statement the trading stop had underlined questions previously raised about the structure of the market and “particularly the role of transparency”. Vladimir Putin’s invasion of Ukraine had raised concerns over the supply of nickel from Russia. The Moscow-headquartered Nornickel is the world’s largest supplier of refined nickel, mined in Siberia. The company is led by Vladimir Potanin, an oligarch who is one of Russia’s richest men. He and his company have not been sanctioned by the US, EU, or UK. Amid the market chaos resulting from the invasion, the LME caused uproar among metals traders by cancelling all transactions made on 8 March, a move it said it needed to make to protect orderly trading and prevent smaller members of the exchange from going bust. The LME on Monday said that the movements in the run-up to its trading suspension were “unprecedented”. It has put a 15% limit on daily market moves in metals for physical delivery, which it said had broad support, and will commission its own independent review of the chaos. It said: “The LME fully recognises the impact of these events on a broad spectrum of market participants, and understands that not all participants agreed with the course of action undertaken. The LME sought to act in the interests of the market as a whole and acknowledges the concerns expressed by some market participants.” The exchange said it had already identified one problem with its lack of visibility of trades that happened outside the exchange – known as “over-the-counter” trades – that helped to drive the price up. The FCA will “review the LME’s approach to managing the suspension and resumption of the market in nickel to determine what lessons might be learned in relation to the LME’s governance and market oversight arrangements”, while the BoE will look at LME Clear, the subsidiary that handles the actual transactions. The FCA made it clear that it LME will have to make changes after the turmoil. It said it “expects the LME to consider carefully how recent events should shape its future approach on market structure”. The regulators will also talk to trading firms to assess their risk management.