Global banking regulators have identified Citigroup, Bank of America and Wells Fargo as presenting bigger risks to the financial system than last year. These banks should face stiffer capital requirements to ward off threats. These banks have risen in the Financial Stability Board’s latest ranking of the most systemically important banks in the world. The Board also said Morgan Stanley, HSBC Holdings and Barclays have their buffer levels fall. HSBC’s capital surcharge falls to 2% of risk-weighted assets from 2.5%, while Citigroup’s buffer rises to 2.5% from 2%, according to the Board. Barclays surcharge falls to 1.5% from 2%, Wells Fargo rises to 1.5% from 1% and ICBC of China surcharge rises to 1.5% from 1%. The list is headed by Citigroup and JPMorgan Chase. The group of 20 economies (G20) had agreed after the 2007-09 financial crisis that top banks, whose size and complexity mean a collapse could wreak havoc in markets, should hold extra capital, according to the level of risk they present. The other institutions in the list include Aegon, Allianz, AIG, Aviva, Axa, MetLife, Ping An, Prudential Financial and Prudential.