DEFINITION of 'Five Percent Rule'
A regulation that requires a broker to use fair practices and ethical guidelines when setting the commission rates. The five percent rule stipulates that the broker can change the commission percentage by 5%, either up or down, but can only do so if the change can be legally justified. The rule also applies to other transactions, including proceeds sales and riskless transactions.
BREAKING DOWN 'Five Percent Rule'
The five percent rule is one of the rules of fair practice set forth by the National Association of Securities Dealers (NASD), and which must be followed by members of the organization. The rule itself does not set forth any calculation criterion. Instead, it indicates that the broker should follow guidelines. The rule itself has several exceptions.