Hot tip: don’t move. Do nothing. Take a few deep breaths if you need to. Do not check on your portfolio. Do not look up gold prices. Do not try to figure out what zero-coupon bonds are. If you’re truly investing in stocks–that is, if you’re putting away money that you won’t need for 10 years or longer–just keep doing what you’re doing.

Over history, stocks have been the best place to grow your long-term savings, returning on average 11 percent annually since 1926, as measured by the S&P 500. There is, of course, volatility from year to year. Since 1965 the S&P 500 has fallen as much as 26 percent and risen as much as 38 percent. So don’t put money you’ll need in the next five years in the market–it’s too risky in the short term. But the cost of keeping your long-term savings in fixed-income investments is just too great, especially when you’re trying to beat inflation. On an investment of $30,000, what’s the 30-year difference between earning 6 percent (from bonds or a CD) and 11 percent (from an S&P 500 Index fund)? Half a million bucks.

What about managed mutual funds? According to Lipper Analytical Services, three out of four underperform the S&P 500 Index. Fees are often the culprit. On the same $30,000, the 30-year difference between earning the market’s average return of 11 percent in an index fund and 9 percent in a managed mutual fund that charges 2 percent for fees is nearly $290,000.

Take full advantage of your 401(k), especially if your company offers matching funds. If you don’t, you’re throwing away free money. And don’t forget about an IRA. You can put in only $2,000 a year, but if you start when you’re 25, at 11 percent you’ll have $1.4 million by the time you’re 65.

Yes, that’s 40 years. And that’s the point. Investing is a lifelong endeavor, particularly when you consider that you might easily live 30 years past your retirement. The most important part of the investing equation is time. Forty years from now, will it matter that the Fed cut interest rates last month? Will it matter if the market is down 25 percent this year? It won’t, if long-term market trends hold true.

So no matter what Alan Greenspan says, stay the course, no matter what the market looks like now. OK, go ahead, you can check your portfolio today. But tune out the noise. It’s only a snapshot of your savings–one day with 15,000 to go if you’re 40 now.