8006 Exam Dumps : Exam I: Finance Theory Financial Instruments Financial Markets - 2015 Edition

A portfolio loses its delta neutrality if the delta of the portfolio changes but the underlying hedge is unchanged. The portfolio that will require the most rebalancing will be one whose delta changes by larger amounts in response to a given change in the price of the underlying. The sensitivity of the changes in delta in response to changes in the price of the underlying is measured by gamma. The higher the gamma, the more the portfolio will go out of delta neutrality given a change in the price of the underlying. Therefore Choice 'b' is the correct answer.

A portfolio with a low gamma will maintain its delta over a larger price range for the underlying, and is therefore likely to require less frequent rebalancing. The absolute level of the delta itself does not matter, what matters is the gamma. Vega is irrelevant to the delta hedging decision. Therefore the other choices are incorrect.

The optimal hedge ratio answers the question of how much of the hedge to buy to hedge a given position. If 103.11.e1 is the standard deviation of the asset to be hedged, and 103.11.e2 is the standard deviation the asset being used to hedge against price movements in x, then the minimum variance hedge ratio is given by the expression 103.11.e3. In this question, correlation = 0.00378/(6%*7%) = 0.9. The minimum variance hedge ratio is given by (6%/7%)*0.9 = 0.77

He should therefore hold 0.77 x $10m /$100k = 77 contracts.

[We can also do a direct covar based calculation for the min variance hedge ratio as follows:

103.11.a3

= 0.00378 / (0.07 * 0.07) = 0.7714]

As a bond approaches maturity, its value will be driven less by the time value of money or its coupons, and more by its redemption value, ie the par. Therefore as maturity approaches, its value converges to its par value and this phenomenon is called pull to par.