And to further your point, I don't believe that Denselight was ever a publicly traded entity (pls correct me if I'm wrong). 

Although Denselight was a subsidiary of a publicly traded entity (PTK.V) it does not mean that Denselight (a private entity) is automatically a publicly traded entity.

Incorporated companies are treated as seperate legal entities that can be either public or private and, can be co-mingled within a conglomerate