There is no specific minimum investment required for the E-2 Investor Visa. The investment must be substantial and sufficient to develop and operate the business, and the amount required can vary depending on the type of business and industry. Generally, the investment should be large enough to create jobs and stimulate the U.S. economy. A good rule of thumb is that the investment should be at least $100,000, but this can vary depending on the business plan, industry, and other factors. The U.S. government will evaluate the investment to determine if it is substantial and meets the other requirements for the E-2 Visa. It is important to work with an experienced immigration attorney who can advise on the specific investment requirements for the E-2 Visa based on your business plans and circumstances.