An idiomatic phrase that is usually used by a lead underwriter to indicate that the securities of a new public offering issue, set aside or reserved for sale to institutional investors (hedge funds, banks, financial firms, etc.) have been all taken up. The main goal of underwriter is to sell new issues, while setting to determine the price at which all of the available securities will be sold to investors. It has to make sure the security underpriced.

Pot is clean is also known as fully subscribed.