Just take a look at the iShares Treasury Inflation Protected Securities Fund ( TIP ), a $12.3 billion portfolio representing the market for Treasury Inflation Protected Securities (( TIPS )). Average daily volume for TIP ballooned in March to levels not seen since October 2008 as the fund racked up its first net capital inflow in 16 months. Like conventional Treasury obligations, TIPS pay a fixed rate of interest but TIPS' par value rise with inflation, as measured by the Consumer Price Index (( CPI )).