Depends on the definition. The wikipedia editors think it is:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Derivative_%28finance%29#Mortgage-backed_securities" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Derivative_%28finance%29#Mortg...</a>