The E-2 visa allows investors to live, work, and grow a business in the U.S. However, it is a non-immigrant visa classification and the visa applicant does not plan to make the U.S. their permanent home. That means that E-2 visa holders can’t go directly to a green card (i.e., legal permanent residence).
If permanent residency is your goal, it’s recommended that you apply for another immigrant classification (i.e., EB-5 visa, marriage-based visa, etc.).
An E-2 treaty investor visa can be applied for from within the United States if the applicant has legal status such as an F-1 student visa, from another country or from their home country. The applicant does not have to currently reside in a treaty country as long as their citizenship is from a treaty country.