The proper way to invest is to invest in fundamentals. This means to look at the growth of the company and their financial reports.
If you did your research and invested in the companies fundamentals, don't need to worry about short term paper losses. Any dip in price means that the potential for returns is higher. Buy the dip.
However, if you bought into the stock without much research, you may have bought into a falling knife. Remember, a fallin...