If one can backup and use a fuzzy enough lens, one can just ask "how should society calculate the total benefits here" but the problem is this begs the question of whether it's proper for the state to just ask these questions.

My impression is that none of the insider trading proponents are also proponents of the view that it's not theft to take money that falls off the back of an armored car because "it's hard to who it belongs to" and "we might well benefit from this money more than whoever it really belongs to" but their arguments seem the same. Further, the average people finding money on the street probably really do need it more than your average insider trader.

> If one can backup and use a fuzzy enough lens, one can just ask "how should society calculate the total benefits here" but the problem is this begs the question of whether it's proper for the state to just ask these questions.

But in the case of insider trading, there is no such person. Lambdapie identifies that there is a cost (yes!), but that cost only exists at a fuzzier level than "the person stolen from". Trying to examine at a finer level doesn't make sense.