I have a friend who always shows signs of obvious loss in gambling, and he always shows body signs like he doesn't want to talk to anyone and always looks far, always trips himself because his mind is wandering.
It is human nature to feel sad when experiencing a loss, especially losing a big amount of money. That's why you need to limit your money to use in gambling. Limit your funds (money) is the way to avoid losing all your money in 1 night. Regarding the body signs, the sadness can be reflected in a suddenly quiet or often daydreaming or something else. Each person may have a different way to express their sadness. I have a friend that becomes more emotional when he experienced a big loss in gambling or trading. 