What are the factors that determine the spread between agency securities and Trea suries? If agency and Trea sury securities are perceived to have the same risk, why may there still be a positive...

What are the factors that determine the spread between agency securities and Trea suries? If agency and Trea sury securities are perceived to have the same risk, why may there still be a positive spread between their prices?

Defi ne exchange rate, foreign currency, and foreign exchange market