"If your portfolio is largely within an IRA or other retirement plan, consider rebalancing every quarter," says Womack. "If it is regular, taxable money, consider at least annually, perhaps more during extremely volatile periods. For rebalancing strategy to work, you must own assets that don't react the same way over differing market conditions."
Mistake No. 6: Abandoning your investment strategy
"Creating a plan such as dollar-cost averaging and sticking with it under all market conditions is the way to maximize your returns," says Kimmel. "Human nature makes it difficult for the average investor to stick to an investment strategy unaffected by emotion. Sometimes it's fear; sometimes it's pure greed. Either way, allowing emotions to affect your investing decisions is certain to damage your financial future."
"It's human nature to chase hot sectors that have already made a significant move," he says. "It's also natural to panic and sell-out when everyone else is doing the same."
While it may be the natural thing to do, it's not the smart thing, according to Womack. "It's important to have an investment strategy and stick to it. Remember: If the headlines are full of it and everyone else is doing it, you're probably too late."
There is, of course, much more to the maintenance of an investment portfolio that may well help you sleep during these scary investment times. However, sticking with these common sense fundamentals will go a long way toward achieving that end.
For more help with investing, see Bankrate's investment calculators.
William J. Lynott is a freelance writer based in Pennsylvania.