Liquidity may be defined as the ability to buy or sell a bond within a reasonable period of time and at a reasonable price. A simple way to compare two bonds is through the use of Trade Reporting and Compliance Engine (TRACE) daily volume data. The data represents the daily aggregation of each reported trade throughout the day. The existence of reported volume data can be indicative of the frequency of trading. For example, if a bond has volume data for 20 of the last 22 trading days, then it trades relatively frequently—nearly every day. The volume data itself can also indicate the size in which it trades daily. For two bonds, we can compare the turnover rate, defined as the total volume traded in 22 days as a percentage of the amount outstanding. For example, a bond may be considered more liquid relative to another one if a larger portion of its total outstanding is traded over a one-month period.