I am an equities trader taking a course in futures. I asked a question that the PFGBest instructor couldn't answer and also the best real trader I know (a San Diego well-known trader) and he didn't know either. I was hoping some one here might know an answer. What is the reason that initial margin and maintenance margin are different? By my reasoning, margin requirements are protecting the exchange and secondly the broker against the retail trader. It is a limit on leverage which is a deadly game in the wrong hands with potential of systematic risk. So if margin (= protection) is needed then why have two different levels? Thanks in advance for your input.