If John's horse trading put himself or his loved ones into the poor house, that would be an issue. I now some guys have their tongues in cheek, but some guys are honestly wondering perhaps.
Yup, did counseling for 35 years are part of my professional life as well.
While just watching from a distance, which is all this is, my speculative opinion is that John knows exactly what he's doing and having fun at it. It hurts no one. His "losses" are little more then renting or leasing and I suspect much less.
It is his hobby. Horse trading for profit or just for fun is a sport, a hobby, a pastime, an interest. Guys spend a bunch more on their hobbies. Sports tickets, golfing fees and equipment, or you name it. I horse traded cars and trucks for 35 years, as did my dad before me. Even made a buck or two along the way. It's harmless fun and it has a practical side.
Now back to our regularly scheduled programming.