the capital market structure, which institution regulates and supervises the securities market in many countries, including the United States?

The institution that regulates and supervises the securities market in many countries, including the United States, is the Securities and Exchange Commission (SEC). The SEC was created in 1934 in response to the stock market crash of 1929 and is tasked with enforcing federal securities laws, protecting investors, maintaining fair and efficient markets, and facilitating capital formation.

Other countries have similar regulatory bodies; for example, in the United Kingdom, it's the Financial Conduct Authority (FCA), while in Canada, it varies by province with organizations such as the Ontario Securities Commission (OSC). These agencies work to ensure transparency, reduce fraud, and create a stable environment for trading securities, promoting confident investments within the capital markets.