For example, during the 2001 tech boom/bust a lot of tech companies went bankrupt in a very short period of time. As a result a lot of tech employees saw the value of their stock/options drop to zero (effectively). The speed in which the bust happened caught a lot of people off guard.
It is generally a good idea to move at least some of that money into a diversified portfolio as soon as possible. But folks often put this off because they don't want to pay the cap gains taxes and/or they think the stock will keep climbing.
There is no right way of doing it, you’ll never sell at the top. At least the right moment is when you can use the money for a project.
This is likely closer to reality, if one is cryptocurrency savvy.