Positivity bounds impose constraints on the dimension-8 SMEFT parameter space as a direct consequence of fundamental QFT principles. In this talk, I will first review the general aspects of the Standard Model EFT framework, covering the matching and mixing of higher-dimensional operators, as well as global fits and the inverse problem—inferring UV information. I will then introduce the methodology of positivity bounds, highlighting their role as a complementary tool not only for constraining parameter space but also for restricting the RGE running behavior of dimension-8 operators. Finally, I will discuss the potential power of positivity in addressing the inverse problem.