Theexchangethat lists and trades the futures contract sets theminimum initial margin rate. This margin is required as collateral to ensure performance under the contract. The exchange determines this rate based on the volatility and risk of the underlying asset, and it is subject to adjustment depending on market conditions.
Other options:
* Investment dealer: Acts as a facilitator but does not set the margin rates.
* Buyer/Seller: Must meet the margin requirements but do not set them.
References:
* Volume 1, Chapter 10:Derivatives, section on "Futures Contracts" describes the role of exchanges in setting margin requirements.