A privately held company is a company which is not publicly listed on a stock market and consequently cannot be openly bought or sold. Often it is owned by a family or a small group of shareholders. Private companies are often small, but some are amongst the largest companies in the world. Many public companies started life as private companies. In the United States, private companies are held to different auditing standards than public companies. Private companies do not have to file with the U.S. Securities and Exchange Commission (SEC). This makes it harder to find financial information on private companies.