Normally with true day trading you will have sold all of your positions before the end of the day. ALL of them, so you are totally liquid when the bell rings. If you buy it and it immediatley goes down you sell and either try a new stock or get in at a lower price and then sell when it goes up.

With swing trading you don't pay nearly as much in fee's because you can hold stock for quite a few days or even a couple weeks. Riding through the lows of the day and the highes until you meet your desired gain.