最優惠利率是最低利率嗎???

Yes, it is normally correct as banks loan out personal loans with interest rate expressed as prime rate 最優惠利率 plus risk premium i.e.2%, 3%,..... The better the credit worthiness you are, the lesser the risk premium. Thus, you can borrow money from bank at lowest interest rate prime rate 最優惠利率. However, some large corporations can borrow money at HIBOR - Hong Kong Interbank Offer rate, which have different tenors: 1M, 3M, 6M or 12M. These interest costs are lower than 最優惠利率.