This is question in similiar style to what is meaning of life?
You can't get any definitive answer to that, everyone uses different set of "rules" or informations to decide if they will sell. Most often they use emotions which is bad no matter what in trading.

Small portfolio of crypto $500, can't get you many trading styles, you probably want to focus on day trading to slowly make it $5000.
Watch out tho, if you are tired or trading long time, you will make mistakes.