Within the futures industry, financial guarantees required of both buyers and sellers of futures contracts and sellers of options contracts to ensure fulfilling of contract obligations. FCMs are responsible for overseeing customer margin accounts. Margins are determined on the basis of market risk and contract value. Also referred to as performance-bond margin. Financial safeguards to ensure that clearing members (usually companies or corporations) perform on their customers' open futures and options contracts. Clearing margins are distinct from customer margins that individual buyers and sellers of futures and options contracts are required to deposit with brokers.