I remember of a friend who gave up his studies and went all-in on AMP coin (Synereo - if you remember the project). By saying all-in, I don't mean that he invested any money on it but all his time. He worked as a programmer for them and used to earn $300 worth of AMP each month. He did this for at least 3 years, the project did well and he almost became a double millionaire when the spike occurred in markets during 2017 when BTC was $14k and reached $20k. But he kept the coins as it is, didn't sell them when I even advised him to do so and later when the crash happened, the project itself came to an end putting all his work and savings under the grave. So, you need to know when to sell as that's too an important part of trading.