OTC

Abbreviation for over-the-counter, medication available from a pharmacy without a doctor's prescription.

OTC

Shares not traded on any of the major exchanges, such as the London Stock Exchange (LSE) and the New York Stock Exchange (NYSE). Over-the-counter shares are traded directly through a network of computers and over the telephone, rather than through an auction market.

In the USA, trading in OTC or unlisted securities is monitored by the National Association of Securities Dealers (NASD). The shares are often unlisted because they do not qualify for a listing, they tend to be more thinly traded and more volatile. In the USA details of OTC shares and their market-makers can be found in the daily publication The Pink Sheets.