The defining features are not frequency or style. They are loss of control over starting and stopping, continuing despite clear damage to finances, work, or relationships, and the activity taking priority over things that used to matter.
It is easy to hide because trading is respectable. The same behaviour that would be alarming in a casino reads as ambition in front of a terminal, and the industry language of discipline invites people to treat a clinical problem as a character flaw.
It is treatable, and the treatments are the ones used for gambling problems rather than trading education. If any of this is familiar, see gambling-disorder-signs for the markers and problem-gambling-help for where to start.
Related: gambling-disorder-signs, problem-gambling-help, dopamine-and-variable-rewards, loss-of-control