No, when futures are approaching maturity, exchanges usually don't lower the margin ratio, let alone lower it. On the contrary, as the delivery date of futures contracts approaches, the exchange will gradually increase the trading margin ratio. Margin refers to the funds paid by the buyer or seller in accordance with the standards set by the trading market, which are specially used for settlement of order transactions and performance guarantee. The purpose of margin is to maintain the liquidity required for the transaction to continue.