Day Trading

I have heard of someone who earn a living from full-time day trading. Those days when internet hadn't existed, housewives roamed trading houses when their children were in schools.  Stock buying and selling takes place within the same trading day before the market closes for the day.  If you are smart and lucky, you will be lucky enough to make some quick profit within a day.

 

Now that in this modern age, everything is just a click away and that makes stock transactions a breeze.  I always have doubt in my mind though, what if the stock plunges after I bought it?  Do I cut loss by selling it before the market closes for the day or keep it?  Guess I will have to take up daytrade courses from those stock gurus before taking the bold step.