TD Bank stock dropped more than 7% on Thursday after the firm was placed under a growth limitation and fined more than $3 billion by a group of U.S. regulators who found that deficient internal safeguards at the bank had failed to prevent financial crimes including drug trafficking and terrorist financing. On Thursday the Office of the Comptroller of the Currency, the Federal Reserve, the Treasury Department’s Financial Crimes Enforcement Network, known as FinCEN, and the Department of Justice together issued actions against TD, the 10th-largest U.S. bank by assets. FinCEN said its $1.3 billion fine against TD for violating the Bank Secrecy Act—the primary law in the U.S. that aims to prevent money laundering—was the largest penalty against a bank in the Treasury Department’s history.