Here's an interesting article about the downside of stock investing. I completely agree with this statement:

"Stock prices are only important on two occasions: First, when you are presented an opportunity to buy a good business at a cheap price, and second, when you can sell a once-undervalued business at or above fair value. Any other time, they're meaningless."

Perhaps this is the mindset of a long-term investor. I'm sure day traders would beg to differ...