Series FF Stock is a hybrid between Common Stock and Preferred Stock. Corporations sometimes issue Series FF Stock to founders at the time of incorporation in order to facilitate sales of stock by founders in connection with future equity financings.

The shares mostly have the same attributes as Common Stock with the exception that if they are sold by the holder in connection with an equity financing being conducted by the Company, they convert to shares of the same series of Preferred Stock that the Company is issuing in the financing.