Yep, this is why pro's have clearly established stop-loss and take-profit levels before they enter a trade.

Exactly. Take the 300%+ return . Get out of the game ahead. Doubling down is risky.

Heck at least pull your principle out and ride the rest.

Hindsight bias.

He probably shouldn't have gambled the $12k to begin with, even though the first spin of the wheel turned out ok.

Assuming $12k is a lot to this guy.