Enough to be substantial relative to the cost of that business and to show a real commitment to its success. There is no fixed minimum; a modest business purchased almost entirely with the investor's own committed funds can be substantial, while a small stake in an expensive one may not be.
Proportion and commitment, not a threshold
Hypothetical example: the cleaning business is priced at a figure that covers goodwill, two vans, floor-care machines and existing contracts, and the buyer will add working capital for the first six months. The substantiality test compares the invested amount with the total cost of purchasing or establishing the enterprise. Where the investor's committed funds cover nearly all of that cost, the proportion supports the case.
Prepare a table listing purchase price, equipment, deposits, licences and working capital, each tied to a receipt or agreement. Loans secured by the business's own assets do not count as the investor's funds at risk, while loans secured by the investor's personal assets can. Consular fees for the E-2 application follow the Department of State schedule, and any USCIS filing for a change or extension of status follows the G-1055 fee schedule; confirm both before budgeting.
Reciprocity terms for visa validity should be checked on the official site rather than assumed.