The New York Stock Exchange (NYSE) underwent significant changes between World War I and 1971. In the 1920s, speculation in industry and markets led to rapid growth. This came to an end in 1929, triggering the Great Depression. The US government decided to rebuild confidence in capital markets by enacting the New Deal, which established regulatory agencies. The Securities Act of 1933 and the Securities Exchange Act of 1934 were significant changes that led to the creation of the Securities and Exchange Commission (SEC). The SEC’s job is to regulate trading practices, ensure transparency, and prevent fraud. These reforms reduced the excesses of previous speculation, making the financial environment more accessible and stable. As technology advanced and more people from the middle class began investing, the NYSE helped fuel economic growth after World War II, providing funding for the war effort. By 1971, the NYSE had become a more transparent, regulated, and inclusive way to promote economic growth in the United States.