Ancient Romans are often associated with economic practicalities, rather than with theoretical thinking and macroeconomic canvases. A closer look at the available evidence permits to extract a much more chromatic picture in which we can detect traces of awareness of structural, long-running developments and change, masked signs of economic grown, stagnation and crises, as well as deeper considerations about the interplay between economy and society. The interplay between economic performance and social expectations and norms is a constant factor across literary genres. Yet beyond the idealisation of the ethical umbrella under which businesses should operate, ancient authors also discussed dysfunctionalities that challenged mentalities and regulations. With help of theoretical tools such as economics of information and behaviour economics, my sub-project aims to investigate discursive and practical aspects of speculative businesses and financial practices that navigated between the legal and the illegal, and that challenged legislators, moral observers and actors. One of the aims of my research is to better understand how the dynamic notions of fair and unfair profit were constructed, articulated, and debated in different types of genres, from the comedies of Plautus to the moral treatises of the early Christian author Tertullian and the legal literature. The project will also scrutinise and compare evidence of ambiguous economic practices in epigraphic and papyrological sources and evaluate the effectivity of enforcement mechanisms that prevented from wrongdoings and dishonest behaviour. In this regard, I am particularly interested in how soft norms opened the door to suspect trade; e.g. how business relationships often operated between the shadows of general rules and abstractions. Another focus of my research will be the study of the symbiotic relationship between knowledge and speculation leading to unfair market advantages. Authors such as Cicero, Pliny the Elder and Seneca i. a. will underpin my examination of the conceptualisation of ‘financial complexity’ in ancient Roman mentality. To what extent did Romans construct negative discourses of complicated contracts and forms of impersonal financial intermediation and agreements that disengaged actors from fundamental responsibilities? The economic landscape of urban Roman businesses is highly dominated by the influence of professional guilds and collaborative enterprises. To what extent were these organisations engaged in practices that circumvented norms of free competition to embrace ambiguous collusive practices? The extensively detailed coverage of transfers of property rights via inheritances, legacies and donations will further offer a valuable caseload to examine how these forms of enrichment could escape regulations and legal limitations.