People keep saying this but I'm still not sure I buy it. Everyone in the finance industry has some excuse for why their particular gig deserves to exist (HFT /

People keep saying this but I'm still not sure I buy it. Everyone in the finance industry has some excuse for why their particular gig deserves to exist (HFT / hedge funds / shorts) but economics are complex and having a plausible-sounding reason doesn't mean it actually does help the economy / markets function in the long run. Do you have any examples of shorts actually help uncover fraud? Or is it more just when the fraud is uncovered (by someone else, say a 3-letter federal agency) the shorts make money, but they had no hand in actualizing the outcome.