Trade must already be established at the time the E-1 visa application is filed. Investments, however, may be prospective, provided that the funds are irrevocably committed to the investment, contingent only upon the issuance of the visa. Investment funds may come from any country, including the U.S., as long as they are controlled by the investor applicant.
Substantial trade is that volume sufficient to ensure continuous flow (numerous transactions over time) of international trade between the U.S. and treaty country. There is no value or volume minimum. However, smaller businesses are expected to yield income sufficient to support the treaty trader and his or her family.