Speaking in Rome, Joachim Nagel, Bundesbank president, said it was not yet clear what limit consumers should hold on potential digital euros. Citing research by ECB economists, Mr. Nagel said that 3,000 digital euros per person could effectively limit the impact on bank liquidity risk, but the latest Bundesbank research suggests the optimal amount could be between 1,500 and 2,500 digital euros per person. He said he would study carefully to determine the optimal value of this upper limit. Previously, Nagel has said that technological innovation poses a challenge to the future of central banks, calling on officials to accelerate the pace of adaptation, including the launch of a digital currency. The European Central Bank has entered the next phase of the digital euro project in 2023, preparing for the issuance of the currency in the coming years, but a final decision has not yet been made.