An American Depositary Receipt (ADR) is a share of stock of an investment in shares of a non-US corporation. The shares of the non-US corporation trade on a non-US exchange, while the ADRs, perhaps somewhat obviously, trade on a US exchange. This mechanism makes it straightforward for a US investor to invest in a foreign issue. ADRs were first introduced in 1927. Two banks are generally involved in maintaining an ADR on a US exchange: an investment bank and a depositary bank. The investment bank purchases the foreign shares and offers them for sale in the US. The depositary bank handles the issuance and cancellation of ADRs certificates backed by ordinary shares based on investor orders, as well as other services provided to an issuer of ADRS, but is not involved in selling the ADRs.