Once the original lender has a sufficient number of mortgages,the lender will bundle the mortgages into an MBS. An MBS is a number of different mortgages that are bundled together, and sold in such a way that different MBS products have different risk levels. In this way, investors can choose how high a risk they are willing to accept. To reduce the risk, one can also buy a hedge for default risk, such as a Credit Default Swap (CDS) that we discussed in Chapter 4.