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Dumb things to do when Investing

1. Buy the top performing mutual funds or stocks. Quick-hit winners are concentrated and volatile, equally capable of being at the bottom of the charts.
2. “Diversify” by owning a lot of funds that hold the same kind of securities. You are not really diversified when the funds holds the same sort of stocks. You should own a variety of asset classes.
3. Try to do market timing, since it likely that you will miss out more money than you will make.
4. Lose faith. Bailing out of long term investments when things look bad in the short term.