Professional trader and poker player will say the same thing: -You lose the most when you are sure that you will win
Professional poker players usually don't celebrate victory until the river and they don't admit defeat prematurely, before the final card is played.
If they celebrate before the cards open, they can't grab huge amount of chips. They are too silent and normal when it comes in facial expressions whenever they are win or lose. Poker players don't play using their emotions, unlike in trading, we can feel if the coin will push its momentum or change its direction. Even you are pro in poker, you cannot use 100 percent your skills in trading.