treaty exists between the two governments then only the lat type i.e. the employment based investment visa is applicable.

Treaty Trader visa

This visa may not be an investment visa in the real sense, as it does not require any monetary investment. But it requires a record of ongoing transactions such as imports or exports between your country and the USA.

Treaty Investor

Treaty Investor visa requires a substantial amount of investment into real, operating business in the US. The investor needs to have the control of funds and the investment should be substantial i.e. it should be able generate a substantially larger amount of income than just what would be enough for the investor and his family to live.

Employment Based Investment Visas

This is a new category of investment visas for persons making an investment of US $ one million or more and creating full time employment for ten or more US workers. Investments of less than one million dollars also could be acceptable in rural or certain targeted areas of employment. The main attraction of this visa is that it entitles the qualifying investor and his immediate family to rights of residence, the so-called "Green Card".