President Barack Obama sent Congress proposed legislation on the so-called Volcker Rule that would ban banks from hazardous trading and impose limits on how large they can grow. The five-page plan released today seeks to prohibit lenders from trading solely for their own profit and to stop them from grabbing more than 10% of the total liabilities in the banking system through acquisitions. The measure instructs regulators to block mergers that would put bank market share over the limit, unless they are acquiring a failing bank with approval from regulators. The proposal, named for its main proponent, former Federal Reserve Chairman and White House adviser Paul Volcker, is aimed helping prevent a repeat of the worst financial crisis since the Great Depression by reducing risk-taking by banks. The proposed limit on liabilities is similar to the existing cap on bank deposits. US commercial banks held $10.4trn in liabilities as of Feb. 17, according to data from the Federal Reserve. JPMorgan Chase & Co. held $1.5trn of total commercial bank liabilities as of Dec. 31, according to the Federal Deposit Insurance Corp. Charlotte, North Carolina- based Bank of America Corp. had $1.3trn and New York-based Citigroup Inc. $1trn. An exception would be made for acquisitions of “one or more banks in default or in danger of default.” That language would likely allow acquisitions similar to those that took place during the worst of the financial crisis; the measure also would allow banks that are already over the 10% limit to acquire small banks that don’t change their market share.