A European company issues a five-year euro-denominated bond with a face value of EUR50,000,000. The company then enters into a five-year currency swap with a bank to convert the EUR exposure into USD exposure. The notional principals of the swap are EUR50,000,000 and USD70,000,000. The European company pays a fixed rate of 5%, and the bank pays a fixed rate of 4.5%. Payments are made semiannually on a basis of 30 days per month and 360 days per year. The payment from the bank to the company at the end of Year 4 is closest to:
A. EUR1,250,000.
B. USD1,750,000.
C. EUR1,125,000.
Answer = C “Swap Markets and Contracts,” Don M. Chance Section 3.1 The bank’s payments are based on a notional principal of EUR50,000,000 and an interest rate of 4.5%. The payment is: EUR50,000,000 × (.045) × (180/360) = EUR1,125,000.

这里的180天怎么来的？ Year 4怎么理解？