Abstract: In countries with weak institutions, oligarchs often hide enterprise ownership behind related individuals, holding companies, and other entities to protect assets from competitors and the state. Connections among such entities represent a network that characterizes the nature of oligarch control. We argue that the optimal choice of network resolves a tradeoff between opacity and loyalty—more distant and diffuse ownership reduces the transparency of oligarch ownership, at the cost of increased risk of betrayal. We explore this idea in the setting of contemporary Ukraine. Exploiting data from business journalists, firm registries, and records of joint stock companies, we characterize the ownership networks of Ukrainian oligarchs. Seeking to explain variation in the character of such networks, we explore the role of enterprise and oligarch characteristics that affect the tradeoff between opacity and loyalty.