U

Underlying Securities

The specific security that is bought or sold by exercising an option.

Underwriting

The purchase for resale of a security issue by one or more investment dealers or "underwriters." The formal agreements pertaining to such a transaction are called "underwriting agreements."

Unit

Two or more corporate securities (such as preferred shares and warrants) offered for sale to the public at a single, combined price.

Unlisted

A security not listed on a stock exchange but traded on the over-the-counter market.