My probability that the presumption of market fraud is a simple contextual mechanism in response to negative fraud tactics has increased to 55%, after analyzing the behavior of certain market actors. The prior was 30% that this relationship is intrinsically logical, but the posterior indicates dependence on specific conditions. The presumption assumes that all investors rely on the integrity of the market price, which is not the case for short sellers, for example, who bet on manipulation. These sophisticated investors do not experience fraud in the same way, questioning the universality of this presumption for all market participants. It is therefore prudent to see this presumption as a conditional tool, not an absolute logical answer to all forms of fraud.