In some way, it's similar to gambling  in day trading you can also lose everything, and it involves minutes to minutes decision making it is not for the faint in heart, I'm not a day trader but I know of some friend who does day trading and has seen them lose substantial amount when they made a wrong decision and the market change unexpectedly if you are a day trader you should only invest what you can afford to lose  
although day trading involves a lot of analysis there are circumstances that the outcome will not favor you, the symptoms of day traders are very similar to gamblers, depression, and anxiety that is why day traders also need a helpline like gamblers.