Margin is an important component in leveraged trading. It's the word for the first deposit you make to begin and keep a leveraged position open. When trading cryptocurrencies on margin, keep in mind that your margin requirements will vary based on your broker and the size of your trade.
In most cases, the margin is expressed as a percentage of the total position. For example, a trade on bitcoin (BTC) may require payment of 15% of the total value of the position before it can be opened. As a result, instead of $5000, you'd only need to deposit $750.