A Broker and Margin Callsby SEC
If you trade on margin, your broker can sell your securities without giving you a margin call. Now is the time to reread your margin agreement and pay attention to the fine print. If your account has fallen below the firm's maintenance margin requirement, your broker has the legal right to sell your securities at any time without consulting you first. Some investors have been rudely surprised that "margin calls" are a courtesy, not a requirement. Brokers are not required to make margin calls to their customers. Even when your broker offers you time to put more cash or securities into your account to meet a margin call, the broker can act without waiting for you to meet the call. In a rapidly declining market your broker can sell your entire margin account at a substantial loss to you, because the securities in the account have declined in value.