Portuguese to English Bus/Financial Finance (general) Investment Funds

I would like to know the best translation, from Portuguese into English, of the term "ativo objeto". Unfortunately, there is no context, this is just a list of financial terms for software purposes. I have found, however, the following definition in Portuguese: "Ativo objeto é a ação da qual se originam os seus derivativos".
Thank you very much for your invaluable assistance!!