The U.S. Supreme Court case Board of Governors of Federal Reserve System v. Investment Company Institute in 1980 revolved around the question whether the Federal Reserve Board had overstepped its authority by allowing banks to offer money market funds, which were similar to mutual funds offered by investment companies. The Investment Company Institute argued that this was a violation of the Glass-Steagall Act, which separated commercial and investment banking activities. However, the Supreme Court ruled in favor of the Federal Reserve Board with a 6-3 decision stating that it did not exceed its statutory authority under federal law when it allowed banks to operate these types of accounts for customers as long as they complied with certain regulations and restrictions designed to prevent conflicts between commercial and investment banking interests.

In the dissenting opinion for the case Board of Governors of Federal Reserve System v. Investment Company Institute, Justice William Rehnquist argued that the majority's interpretation was too narrow and failed to consider Congress' intent when it enacted legislation regulating banks and other financial institutions. He contended that Congress intended to allow banks to engage in activities closely related to banking or managing or controlling banks, including offering investment services similar to those offered by mutual funds. According to him, this broad interpretation is supported by legislative history and previous court decisions interpreting similar statutes. Furthermore, he criticized the majority's reliance on a strict literal reading of statutory language without considering its broader context and purpose.