A securities fraud lawsuit may occur in a variety of forms. Private investors may be able to bring individual lawsuits in state or federal court against the person or company responsible for the alleged securities fraud. Investors can also seek relief for losses related to securities fraud by participating in a class action lawsuit, or arbitration proceedings. Class action lawsuits tend to be most appropriate when a group of investors share common injuries due to securities fraud, usually perpetrated by corporate actions such as insider trading. On the other hand, in some cases, arbitration is the only remedy available for alleged securities fraud. Many contracts that investors sign with brokers require that any disputes be resolved through arbitration. The National Association of Securities Dealers conducts many arbitration proceedings that stem from securities fraud. Even if limited to arbitration proceedings, however, some studies show that investors often are able to recover at least some of their losses, particularly when represented by an attorney.