While crypto is all about decentralized currency and transcending the stupid restrictions of meat space, keeping that coin boils down to doing exactly that. So in order to protect his customers' funds from hackers, Cotten kept all that crypto money in an offline physical "cold wallet" under his sole control -- the crypto equivalent of a 24-bolt bank vault. Except, and this is a very important distinction, nobody would ever allow the head of Deutsche Bank to insist that only he know the combinations to all their vaults, just in case he Scrooge McDucks himself to death diving into a pile of gold coins.
But when Cotten died, he took with him the one place he felt was safe enough to keep the access codes to that wallet: his brain. So far, all attempts to break the encryption on his laptop have been unsuccessful, and while his employees are panicking trying to recall the dude's first pet's name or find a Post-It in his office that reads "Cryptorulez123456789," the conspiracy theories have already started flying. Which makes sense when a guy in a shady industry with sole access to military coup levels of money dies suddenly and mysteriously, with the only offered proof being a death certificate from a country famed for their easily bribed government officials.