Investors make mistakes every day. If they didn't we'd all be as rich as Warren Buffett and we're not.

Here's a list of six such mistakes:

• Follow hot tips. As a blogger on AOL's BloggingStocks, I know that some of the most popular posts are the ones that repeat what Jim Cramer said on his TV show five minutes before the post appears on the blog. The reason these posts are so popular is because lots of people are Cramer Ditto Heads (CDHs). He tells them what to do and they do it. While some use Cramer as a starting point for further research, many are too willing to be led and are not inclined to do their own research.
• Don't know how to research fundamentals. One of the reasons people don't do their own research is because they don't know how. Specifically, one kind of research many people don't know how to do is understanding how a company -- whose stock someone wants to buy -- fits within its industry. Many people would not know how to begin answering fundamental questions such as: Is the industry profitable? Why? How is that profitability likely to evolve? What is the company's market share? If it's a leader, can it sustain that leadership? If it's behind can it catch up? What kind of cash flow does the business generate? How much cash flow is it likely to sustain in the future? Does the market recognize these future cash flows in its price?
• Don't know how to analyze technicals. Many times fundamentals have nothing to do with how a stock performs. For example, in December 2003, Martha Stewart Omnimedia Inc. (NYSE: MSO) stock started going up from $9 when its Home & Garden Television (HGTV) show was taken off the air to $36 in February 2005 when Martha Stewart got out of jail. During that time the company saw its revenues shrink 20% a year and its losses skyrocket. The reason the stock went up is a mystery. But I thought people who were loyal Martha Stewart Ditto Heads (MSDHs) bought MSO as a show of support. Many investors do not know how to analyze money flows that would provide clues to what is driving a stock up or down. This can cause them to buy when they should be selling, or sell when they should be buying.