"Margins" provides an explanation what margin is and their significance in trading futures contracts. It covers different types of margins and introduces concepts such as "marking to market." There are two main types of margins: trading margin collected by a member from a trader and clearing margin collected by the Exchange Clearing house from a member.

It explains that a margin is the cash or marketable securities deposited by an investor with their broker. It also outlines various terms related to trading margins, including initial margin, maintenance margin, margin call, and variation margin. It also mentions different types of traders and their margin requirements. Bona fide hedgers, who produce the underlying commodity, generally have lower margin requirements compared to speculators.

It discusses day traders and spread transactions, which can have lower margin requirements as well. It introduces the role of the exchange clearinghouse, which acts as an intermediary and guarantees transaction performance. Clearing margins are explained as the margin accounts maintained by clearinghouse members.

In conclusion, "Margins" provides a comprehensive overview of margins in futures trading, including their types, calculation, and implications for traders and clearinghouse members. The example scenario helps illustrate the practical application of margin requirements and the importance of maintaining adequate margin levels.