Hi guysBuilding a couple of interest rate models (g2++ & HW Vasicek) and in the process i need to calibrate them to swaptions in the market. My question is regarding the strike price. The swaption prices available in Datastream are all ATM. Does this mean that the different times to maturity of the option will have different strike prices or will they all have the same strike price? I am only usin 10 year tenors.For example I have a swaption where the option expires in 2 years and one where the option expires in 5 years. Both have 10 years tenor. Will they have the same strike price ?

Your first swaption will use the ATM 10-year forward rate starting two years out the and the latter will strike at the 10-year forward rate starting five years out. Unless the yield curve is completely flat for all tenors these rates will be different.