Another indicator that reflects the mood of investors is the outlook of investment advisory services and newsletter writers.
But others say newsletter writers aren't necessarily recommending a stock just to make a quick buck off subscribers.
And many newsletter writers who engage in seemingly unsavory practices say their performances speak for themselves.
A well-timed market call could mean huge rewards as a highly paid investment strategist, a sought-after portfolio manager or a popular newsletter writer.
That kind of performance has been just what the doctor ordered for the spirits of newsletter writers.
Throughout the 1640s and 1650s he was a prolific and energetic professional newsletter writer.
At one point, Mr. Moore considered that unhappy newsletter writers should band together in a class action.
Companies and newsletter writers regularly mislead the public about how well they're doing, Mr. Weiss said.
One of those attending was Mark Roberts, a newsletter writer who then wrote a tough report on Enron.
A recent study of five newsletter writers shows that the funds they run did as well as or better than their newsletters.