# What is CMS Spread Option Single Look? In what ways is it different from CMS Spread Cap/floor?

What is CMS Spread Option Single Look? In what ways is it different from CMS Spread Cap/floor? Also, what's strike shift? What's its function in CMS spread options' pricing? Thanks.

A single look CMS spread option is simply an option on the difference between the two forward CMS rates and a chosen strike $$K$$ on a single expiry date $$t$$. A CMS spread cap is then a strip of options and pays on each $$t_i$$ from $$t_1$$ to $$t_n$$. Both types are quoted by brokers such as Tullet. Both products allow the investor a view on the shape of the yield curve.