Past studies in supply chain management have focused on dyadic relationships (e.g., buyer–supplier), as all relationships in a network begin with a dyad. However, dyads do not capture the essence of a network. We posit in this paper that triads are the fundamental building blocks of a network. To begin considering triads in supply networks, we build on two extant bodies of literature — the buyer–supplier relationship and supplier–supplier relationship literature which offer us the context of buyer–supplier–supplier triads. By doing so, we are taking the first step toward cracking the internal dynamics of triads in supply networks. To build theoretical propositions, we apply balance theory and the structural-hole concept. We identify nine triadic archetypes of buyer–supplier–supplier relationships and state key propositions that aid in decision making in supply networks.