Swap valuation. An interest rate swap is an agreement in which 2 parties agree to periodically exchange cash flows over a certain period.The amount of money exchanged depends on the principal amount, the floating and fixed rate. Swaps can both be for hedging and speculating as well as lowering the funding cost for a company or country. The most common type of interest rate swap is one in which Party A agrees to make payments to Party B based on a fixed interest rate, and Party B agrees to make payments to Party A based on a floating interest rate. The floating rate is tied to a reference rate (in almost all cases, the London Interbank Offered Rate, or LIBOR). For example, assume that Charlie owns a $1,000,000 investment that At the time a swap contract is put into place, it is typically considered “at the money,” meaning that the total value of fixed interest rate cash flows over the life of the swap is exactly equal to the expected value of floating interest rate cash flows. In the example below, an investor has elected to receive fixed in a swap contract.