If I know the outcome, why would I bet largw before the outcome is to be publicly revealed? I just wait and bet only if the market is wrong when the reveal is

If I know the outcome, why would I bet largw before the outcome is to be publicly revealed? I just wait and bet only if the market is wrong when the reveal is imminent. Isn't this a realy good money laundering avenue? I sell you guaranteed outcomes, for a fee ofc.