Stock broker misconduct can result in fraud claims against both the individual broker and the brokerage firm with which the stock broker is affiliated. Some of the most common types of stock broker misconduct include engaging in excessive trading, failing to diversify an investor's portfolio of assets, misrepresenting certain material facts to investors, acting without the investor's permission, or simply taking some action that is not consistent with the investor's best interests in terms of personal desires and investment goals. Since stock brokers are paid on commission, which, in turn, is based on the transactions that they generate, some stock brokers may engage in excessive transactions on behalf of clients in order to increase their commissions, even when doing so is not in the best interest of the clients, which commonly known as "churning". Likewise, a stock broker is not unauthorized to undertake transactions for which the client has not given his or her permission. Unauthorized trading, selling, and/or buying can result in fraud claims against a stock broker.