A snowball whose coupon depends on the previous coupon plus the difference between a strike level and the 10-year constant maturity swap (CMS) rate, rather than LIBOR. The following formula demonstrates how the coupon of a CMS snowball is calculated:

Coupon = [previous coupon + strike% − 10YCMS]

Where 10YCMS denotes the 10-year constant maturity swap rate.