ADS (American Depositary Shares)

An American depositary share (ADS) is an equity share of a non-U.S. company that is held by a U.S. depositary bank and is available for purchase by U.S. investors. The entire issuance of shares by a foreign company is called an American Depositary Receipt (ADR), while the individual shares are referred to as ADSs. But the terms American Depositary Shares and American Depositary Receipts are often used interchangeably.

ADSs allow foreign companies access to a wider investor base and the world's most sophisticated financial marketplace. The main drawback of ADSs for investors is that there is still some currency risk, even though they are denominated in U.S. dollars.

A single ADS often represents more than one share of common stock. Further, ADSs can "gap" up or down outside of U.S. trading hours, when trading is happening in the company's home country and U.S. markets are closed.

For example, South Korea's Woori Bank, a subsidiary of Woori Financial Group, has ADSs that are traded in the U.S. The bank's ADS gapped up by $0.03 on July 20, 2016. Technical analysis of the price action on this ADS shows that for the past decade, its price continued higher two-thirds of the time after a gap up.
(source: Investopedia)