First off, some clarifications on terms. "Psychopathy" is a personality disorder, not psychosis or insanity. Second, "psychopathy" is largely a synonym for both "sociopathy" and "antisocial personality disorder." (See the first and second paragraphs of the Wikipedia entry under "Psychopathy.") Some people try to differentiate psychopathy and sociopathy in terms of their origin. But officially "psychopathy" is the main heading, "sociopathy" is just a more benign-sounding synonym, and "antisocial personality disorder" is the DSM designation for psychopathy.
And if you know about personality disorders, then you know that someone with a personality disorder can be perfectly functional. The big question is whether they observe the sorts of boundaries that keep them out of jail, or whether the disorder is so out of control that they end up colliding with the authorities.
From the Smithsonian article:
When psychologists talk about psychopaths, what we’re referring to are people who have a distinct set of personality characteristics, which include things like ruthlessness, fearlessness, mental toughness, charm, persuasiveness and a lack of conscience and empathy. Imagine that you tick the box for all of those characteristics. You also happen to be violent and stupid. It’s not going to be long before you smack a bottle over someone’s head in a bar and get locked up for a long time in prison. But if you tick the box for all of those characteristics, and you happen to be intelligent and not naturally violent, then it’s a different story altogether. Then you’re more likely to make a killing in the market rather than anywhere else.