Addiction is the inability to stop consuming a chemical or pursuing an activity despite causing harm.
Very much the same happens to people who trade.
Here are some signs of addiction:
You spend far too much of your free time trading
You are trading stocks at work (and it isn’t your job)
The “high” of trying to find the next “moonshot” is the focus of attention
You have feelings for frustration, aggression or attempt to surpress other personal problems...