Ok so now it starts to make sense. With regard to the capital. if you buy 3000 shares and let it go up 50 cents, you make 1,500 dollars. I get this so far. But what if you have 3000 dollar capital and buy the 3000 shares or you have 300 dollar capital with 1:10 leverage and then buy the 3000 shares. Isnt this the same? Cant you just replace capital with leverage as long as you dont make to much risk?

Also there is in the news that a plain crashed, which is offcourse a very terrible event for a lot of people.. However this also effects the stock markets and traders? Now for me I have long term stocks (for a few years) and short term stocks (for a few days). How should you react to this as a trader?

I guess I just hold my long term stocks and my short term stocks are now downtrending (yesterday). What should I do, wait till they will recover? Or sell them and buyback when they are uptrending again? What do you do when an unexpected negative event hits the stock market and your trades?