One way that a portfolio manager might be able to beat their benchmark is through use of the rolling down the yield curve strategy. This strategy only works if we have an assumption of yield curve stability over time and is not a guaranteed source of return if we assume the yield curve is going to stay constant and it moves we may not generate excess return enabling us to beat our benchmark using this strategy. So that caveat out the way it's then worth going into the numbers around this strategy and the strategy basically says that we need to invest in longer dated bonds than our target investment horizon as opposed to investing in bonds, which have a maturity date that matches our target because by investing in those longer dated bonds and then selling them when we need the cash to liquidate our position. Who generate more return than just buying the bonds with our target maturity? The numbers here on the slide look at a three-month investment horizon. So if we have a three month investment horizon, we could buy and hold a three-month treasury bill that would pay us back its par value in three months time. And in this example, we're told that the current purchase price of a three month treasury bill is 99.5 zero in three months time. We'll get back the par value of 100 and as a result, we can therefore calculate the return that will make in that three month time horizon being a 50 cent gain expressed in percentage terms in relation to the purchase price of 99.5 zero that'll give us a 0.5% return an alternative strategy might be to invest in a six-month treasury bill. That's a longer maturity than our target investment horizon. Well in three months time we could just sell this treasury bill at which point in time. It will only have three months left to maturity. If this treasury bill currently has a price of 98.80 which reflects an upward sloping yield curve. We would need to pay out 98.80 today. We would then receive back from selling this treasury bill in three months time 99.5 zero, which is the same as the current price of a three month treasury bill because this strategy assumes that there is no change in the yield curve over time. So over this three month time horizon, we're going to be making a 70 cent game divided by the initial purchase price of the 98.80 giving us a 0.71% gain over the three month time Horizon more than we would have made had we invested in that three month treasury bill. This seems almost too good to be true that we can generate more return just by buying a longer dated bond than we need but it's worth reiterating that this strategy does make an assumption that the yield curve will remain constant over time. If the yield curve moves, we won't generate this out performance through buying that six month treasury bill rather than buying the three month treasury bill.