How exactly are you going to do an OTC sale for an "obscene amount of fiat" without exposing yourself to extreme risks?
You go to Genesis Trading or Cumberland Mining who telephones one of their nice clients looking to buy. You deposit your coins with them. Their client pays Genesis Trading. When the money is cleared everyone gets what they want.
Plus you get a nice man or woman to hold your hand throughout who won't freeze your arse because you're nothing more than an anonymous reference number on a status page.
No tense, armed handoff down by the bridge construction site with aluminum briefcases full of Benjamins?