You gotta be careful what you read, especially if you are a do-it-yourself investor making portfolio decisions based on what you read. Not everything in a newsletter or on a website will necessarily be true or easily interpreted.

A working paper by professors Kingsley Fong, David Gallagher and Adrian Lee has some findings that may be of interest to do-it-yourself investors. Specifically, DIYers would be well advised to avoid trading just after the market opens and to beware of using limit orders if they don’t have the time or ...