COST on stocks (or any other organization)?

HI! I’m wondering how would a COST scheme work on intangible assets such as stocks? Guess very similar as with the other assets, but I’m not sure. More specifically, how would COST manage the ownership of companies? I understand the fact that a company could be another name for the “cluster of assets” owned by that legal entity. But what about the legal entity itself? How participation in a venture/freedom to associate works under the COST system?