Investing In a Growing Stock Market

I’m writing an article for “U.S. News & World Report” about investing in the stock market. I’m looking to hear from financial advisors, academics or any investment expert who has advice for people playing the stock market that will be important to remember assuming the Dow continues to climb. For instance, if the Dow would fall or climb 1,000 points in the near future, that might panic or overly excite some investors. When falling or climbing 1,000 points should be far less dramatic at 25,000 than if the Dow was at, say, 15,000. If you have certain factors that you feel would be helpful for investors to remember –again, assuming the Dow continues to climb–, I’d be interested in hearing from you.