This 5% increase is actually huge, because the amount of bitcoins in actual free float is very small. The same coins get traded over and over while the vast majority sits in cold storage. A 5% supply sell off would eat up all of the order books, and that's before everyone else starts selling off.

Do note that the selloff would be automatic, huge wallets are monitored 24/7.

If I was Satoshi, I would go a to big bank and sell the private key directly for huge discount. Still a billionaire, no trace.