I'm sure those drug dealers sold the bitcoin they got for cash as soon as possible. They probably thought bitcoin was risky lol and they would of had to resupply their stock of drugs and I'm sure their supplier only accepted cash lol and I doubt they even realized what bitcoin really was because if they did then they'd have realized that and buying bitcoin and waiting 5 years is a much better idea than committing crime and risking incarceration. Although, here's an article of an old drug dealer from silk road in 2012 that held 1,571.5 bitcoin and 1,572.7 bcash for years and then sold it all on an exchange for $19M in early 2018 and then got arrested and sentenced to 42 months in federal prison. He should have just bought a bunch of bitcoin for five dollars each and held them but instead he sold illegal drugs for bitcoin, held the bitcoin for years, then sold them, got arrested, got his money seized, and went to prison for the next 42 months.