Marketable versus Non-marketable
For the Marketable and Non-marketable (Interest) graph, the interest expense is cumulative per fiscal year, which includes the months of October through September. In December and June, non-marketable interest will increase due to semiannual interest payments for Special Issue securities that occur at the end of these months.
Marketable and Non-marketable
Marketable securities consist of bills, notes, bonds, and TIPS. Non-marketable securities consist of Domestic, Foreign, REA, SLGS, US Savings, GAS and Other. Marketable securities are negotiable and transferable and may be sold on the secondary market.