The main purpose of the INVEST Act is to require the federal government to sell its ownership stakes in private companies in order to help reduce the national debt. The legislation aims to ensure that the government is not holding onto investments in for-profit companies and instead uses the proceeds from these sales to pay down what it owes. Key provisions of the Act include a requirement for federal agencies to identify all their equity investments in private companies. This includes various forms of ownership such as stocks, partnership interests, and any rights to acquire these interests.