Digital economies are increasingly characterized by firms that create and capture value without owning the core assets on which their operations depend. This theory-development article advances a coordination-centric perspective to explain how focal firms achieve competitive advantage in decentralized digital ecosystems. Integrating research on asset-light business models, platform governance, and distributed coordination, the article identifies a fundamental shift from ownership-based control to orchestration-based advantage. It argues that firms no longer rely on asset possession but on their capacity to structure and align interactions among legally independent actors through platforms, standardized interfaces, data-exchange protocols, and relational governance mechanisms. The proposed framework conceptualizes the firm as a coordination hub embedded within a network of externally owned assets, where strategic influence is exercised through architectural design and adaptive governance rather than hierarchical authority. It elucidates key mechanisms—including dependence management, dynamic repositioning, and feedback-driven governance—that enable firms to sustain performance under conditions of distributed control and heightened interdependence. Six theoretical propositions specify the causal relationships linking orchestration intensity, ecosystem participation, and resilience to sustained competitive advantage. By reconceptualizing firm boundaries as permeable and relational, the article extends digital business and strategic management theory into fully decentralized contexts. It contributes by clarifying the micro-foundations of non-ownership strategy and by demonstrating how coordination capabilities substitute for ownership as the primary locus of control. The framework further offers managerial guidance for designing and governing ecosystems in which influence must be achieved without asset ownership, positioning orchestration capability as the defining source of advantage in the digital age.