While postneoliberalism is often interpreted as a societal reaction against the deleterious effects of marketization in Latin America, this paper develops a finer-grained Polanyian institutional analysis to gain better analytical purchase on the ambivalent outcomes of postneoliberal reforms. Drawing on recent insights in economic geography, and in dialogue with the Latin American structuralist tradition, we elaborate our framework through a case study of the Argentinian soy boom of the 2000s, identifying forms of market extension, redistribution, reciprocity and householding that facilitated this process. We argue for a multi-scalar approach that balances attention to national and extra-local dynamics shaping the combination of these forms, identified through the lens of the “fictitious commodities” of the soy boom: money (credit, currency and cross-border capital flows), land (in the agricultural heartland and frontier regions), labor (transformed and excluded in a “farming without farmers” model) and, we add, knowledge (biotech). Our analysis identifies internal tensions as well as overt resistance and “overflow” that ultimately led to the collapse of postneoliberal regulation of the soy complex, ushering in a wider, market-radical counter-movement. Refracting double-movement-type dynamics through the prism of heterodox institutional forms, we argue, allows for a better grasp of processes that underlie institutional recalibrations of progressive and regressive kinds.