I have sold one stock in the last eight years. I know some investors may find that hard to believe (and perhaps incredibly stupid), but it's true. I don't sell.

It's been easy to be a buy-and-hold investor given the market's performance over the last several years. Of course, the future may not mirror the past, and I have no doubt that my "no-sell" policy will likely be tested over the next few years. I'm also confident that I won't detour far from my past investment practices.

One reason is that, for the most part, patience has its rewards on Wall Street. I've seen several stocks in my own portfolio that over the years fell on hard times only to rebound nicely within a 12-24 month period.

To be sure, not every stock that declines eventually rebounds. And I don't want to undersell the risks of buying stocks that tumble. Still, investors should not always jump to the often-easy conclusion that a stock that declines is a stock that should be sold.

The following are some investment rules I think are useful for investors:

•	Remember that when you sell, you're assured of at least two bad things happening. Every time you sell, you incur transaction costs. You'll also likely incur a tax liability if you have a gain in the stock. Transaction costs and taxes can have a big impact on your portfolio over time.
•	Maintain a long-term perspective. If you regard your investment horizon as 10 years or more, you're likely to be more willing to be patient with a stock, especially when you believe in the fundamentals of the company. If you buy right, you don't have to worry so much about selling.
•	Remember that investing is a marathon, not a sprint. Give your investment ideas time to work out.
•	Take advantage of price dips in quality stocks to add to positions.