The founder of Vanguard spoke of 8 Rules of Investing that are worth remembering:

• Select low-cost funds
• Consider carefully the added costs of advice
• Do not overrate past fund performance
• Use past performance to determine consistency and risk
• Beware of stars (as in, star mutual fund managers)
• Beware of asset size
• Don’t own too many funds
• Buy your fund portfolio – and hold it