最高信贷评级 meaning in English

tocredit rating
top credit rating

Top credit rating
最高信贷评级
In order to preserve the capital and to meet foreign exchange requirements for market intervention purposes , the exchange fund maintains very high liquidity and restricts its investments to a mix of liquid securities of the highest credit quality
外汇基金为了保障资本以及满足进行市场干预所需的外汇需求，必须保持极高的流动性，并将投资限制在获得最高信贷评级而且流通量高的短期证券的范围内。