Stock that is not registered with the Securities and Exchange Commission (SEC). Under the Rule 144 resale provisions for securities previously issued privately by a company without an SEC registration statement, restricted securities must be held for a stipulated length of time before they can be resold.

The term is also commonly used to refer to any securities held by affiliates that must be sold under Rule 144, regardless of whether the stock is registered. For details, see the section SEC Law: Rule 144.

Restricted securities should not be confused with restricted stock, a form of stock compensation.